gRPC - Google Remote Procedure Call
What is gRPC?
gRPC is a high-performance, open-source remote procedure call (RPC) framework developed by Google. It enables communication between services using HTTP/2 and Protocol Buffers (protobufs) for efficient, strongly-typed messaging.
Why is gRPC useful?
Efficient communication – Uses Protocol Buffers for compact and fast serialization.
Strongly typed – Interfaces are defined using .proto files, enabling code generation.
Bi-directional streaming – Supports client, server, and bi-directional streaming natively.
Language interoperability – Works across many programming languages.
How it works?
Define service – A .proto file defines the service and message types.
Generate code – Tools generate client and server code in multiple languages.
Client makes request – The client calls a method as if it were local.
Server handles request – The server receives the call and processes it.
Response sent – The result is sent back to the client over HTTP/2.
Where is gRPC used?
Microservices – Enables efficient communication between services.
Mobile applications – Due to compact message size and HTTP/2.
Cloud services – Used in systems like Google Cloud and Kubernetes.
Real-time communication – Great for use cases needing bi-directional streaming.
Which OSI layer does this protocol belong to?
gRPC defines application-level service interfaces and message formats.
It operates over transport protocols like HTTP/2, focusing on high-level logic.
It provides structured, reliable RPC services directly to applications.
Is gRPC Windows specific?
No, gRPC is not Windows specific. It is a cross-platform framework supported on Windows, macOS, Linux, and many other systems. gRPC clients and servers can be built and run on any operating system.
Is gRPC Linux specific?
No, gRPC is not Linux specific. While it is widely used in Linux environments (especially for cloud-native and microservices deployments), it runs equally well on Windows, macOS, and other OSes.
Which Transport Protocol is used by gRPC?
gRPC uses HTTP/2 as its transport protocol. HTTP/2 allows multiplexed streams, server push, and efficient binary framing, which are key to gRPC’s performance and scalability.
Which Port is used by gRPC?
By default, gRPC servers typically listen on TCP port 50051. However, this is configurable, and other ports may be used depending on the deployment.
Is gRPC using Client server model?
Yes, gRPC follows a client-server model. The client sends requests to the server, and the server responds using a defined service contract specified via Protocol Buffers (proto files). gRPC also supports bi-directional streaming and asynchronous communication.
Topics in this section,
In this section, you are going to learn
Terminology
Version Info
gRPC |
RFC |
Year |
Core Idea / Contribution |
|---|---|---|---|
Version |
|||
Version 1.0 |
|||
gRPC Public Release (GitHub) |
2016 |
Initial stable release of gRPC, introducing efficient, cross-language RPC communication using Protocol Buffers over HTTP/2 |
|
Semantic Versioning |
|||
GitHub Versioning Guide |
Ongoing |
gRPC follows semantic versioning (vX.Y.Z), ensuring backward compatibility and structured evolution of features |
|
Service Versioning Strategy |
|||
Microsoft Learn |
2024 |
Guidelines for evolving gRPC services without breaking clients, supporting non-breaking changes like adding fields or methods |
setup
setup
Client Request Headers Packet
S.No |
Protocol Packets |
Description |
Size(bytes) |
|---|---|---|---|
1 |
Client Request Headers Packet |
Sent by the client to initiate a gRPC call |
Variable (depends |
over HTTP/2. |
on headers) |
||
:method |
HTTP method (always POST) |
Variable |
|
:scheme |
Protocol scheme (http or https) |
Variable |
|
:path |
RPC method path (e.g., /service/method) |
Variable |
|
:authority |
Server authority (host:port) |
Variable |
|
content-type |
Must be application/grpc |
Variable |
|
te |
Must be trailers |
Variable |
|
grpc-timeout |
Optional timeout value |
Variable |
|
grpc-encoding |
Optional compression method |
Variable |
|
grpc-accept-encoding |
Supported compression methods |
Variable |
|
Custom Metadata |
Application-specific headers |
Variable |
|
gRPC Data Frame (Request Message) Packet
S.No |
Protocol Packets |
Description |
Size(bytes) |
|---|---|---|---|
2 |
gRPC Data Frame (Request Message) |
Carries the serialized Protobuf message |
5 + message length |
from client to server. |
|||
Compressed Flag |
0 = uncompressed, 1 = compressed |
1 |
|
Message Length |
Length of the message (big-endian) |
4 |
|
Message |
Serialized Protobuf message |
Variable |
|
Server Response Headers Packet
S.No |
Protocol Packets |
Description |
Size(bytes) |
|---|---|---|---|
3 |
Server Response Headers Packet |
Sent by the server to acknowledge the |
Variable |
request and start the response. |
|||
:status |
HTTP status (usually 200) |
Variable |
|
content-type |
Must be application/grpc |
Variable |
|
grpc-encoding |
Compression used (if any) |
Variable |
|
grpc-accept-encoding |
Supported compression methods |
Variable |
|
Custom Metadata |
Application-specific headers |
Variable |
|
gRPC Data Frame (Response Message) Packet
S.No |
Protocol Packets |
Description |
Size(bytes) |
|---|---|---|---|
4 |
gRPC Data Frame (Response Message) |
Carries the serialized Protobuf message |
5 + message length |
from server to client. |
|||
Compressed Flag |
0 = uncompressed, 1 = compressed |
1 |
|
Message Length |
Length of the message (big-endian) |
4 |
|
Message |
Serialized Protobuf message |
Variable |
|
Server Trailers Packet
S.No |
Protocol Packets |
Description |
Size(bytes) |
|---|---|---|---|
5 |
Server Trailers Packet |
Sent by the server at the end of the stream |
Variable |
to indicate status. |
|||
grpc-status |
Status code (e.g., 0 = OK) |
Variable |
|
grpc-message |
Optional human-readable message |
Variable |
|
Custom Trailers |
Application-specific metadata |
Variable |
|
s.no |
Use Case |
Description |
|---|---|---|
1 |
Microservices Communication |
Enables efficient, low-latency communication between services in distributed systems. |
2 |
Cloud-Native Applications |
Widely used in Kubernetes and service meshes (e.g., Istio) for internal service communication. |
3 |
Mobile Backend Services |
Ideal for mobile apps due to its compact binary format and HTTP/2 support. |
4 |
IoT Systems |
Facilitates fast and lightweight communication between edge devices and cloud services. |
5 |
Real-Time Data Streaming |
Supports bidirectional streaming for telemetry, logs, and analytics pipelines. |
6 |
Machine Learning Pipelines |
Used to connect ML model servers with data preprocessing and inference services. |
7 |
Cross-Language APIs |
Allows services written in different languages to communicate seamlessly. |
8 |
Internal APIs in Enterprises |
Preferred for internal APIs due to performance, type safety, and versioning. |
9 |
Blockchain and Fintech |
Used in systems requiring high throughput and secure communication. |
10 |
Gaming Backends |
Supports real-time multiplayer game state synchronization and matchmaking. |
S.no |
Feature |
Description |
|---|---|---|
1 |
Protocol Buffers (Protobuf) |
Uses Protobuf for compact, fast, and strongly typed message serialization. |
2 |
HTTP/2 Transport |
Leverages HTTP/2 for multiplexing, flow control, and low-latency communication. |
3 |
Cross-Language Support |
Supports many languages including Go, Java, Python, C++, and more. |
4 |
Streaming Support |
Enables client, server, and bidirectional streaming for real-time data exchange. |
5 |
Contract-First API Design |
APIs are defined in .proto files, ensuring consistency and auto-generated code. |
6 |
Built-in Authentication |
Supports TLS, token-based auth, and integration with systems like OAuth2. |
7 |
Load Balancing & Retry |
Supports advanced features like client-side load balancing and retries. |
8 |
Pluggable Architecture |
Allows integration of custom interceptors, authentication, and logging. |
9 |
Efficient Binary Format |
Smaller and faster than JSON or XML, ideal for performance-critical systems. |
10 |
Error Handling & Status Codes |
Provides structured error responses with gRPC status codes and messages. |
protocol buffers(Protobuf) - Testcases
# |
Test Case |
Description |
Expected Result |
|---|---|---|---|
1 |
Define Simple Message |
Create a basic .proto message with primitive fields |
Message compiles successfully |
2 |
Serialize Message |
Convert message to binary format |
Output is compact and valid |
3 |
Deserialize Message |
Parse binary data into message object |
Fields populated correctly |
4 |
Use Nested Messages |
Define nested message structures |
Nested fields serialized/deserialized correctly |
5 |
Use Repeated Fields |
Define repeated fields (arrays/lists) |
Multiple values handled correctly |
6 |
Use Enum Fields |
Define and use enums |
Enum values serialized and parsed correctly |
7 |
Use Oneof Fields |
Use oneof for mutually exclusive fields |
Only one field set at a time |
8 |
Use Optional Fields |
Define optional fields |
Fields can be omitted without error |
9 |
Use Default Values |
Rely on default values for unset fields |
Defaults applied correctly |
10 |
Forward Compatibility |
Add new fields to existing message |
Older clients ignore unknown fields |
11 |
Backward Compatibility |
Remove or rename fields |
Older messages still parse correctly |
12 |
Field Number Uniqueness |
Ensure unique field numbers |
Compiler throws error on duplicates |
13 |
Reserved Fields |
Reserve field numbers and names |
Compiler prevents reuse |
14 |
Use Map Fields |
Define map (key-value) fields |
Keys and values serialized correctly |
15 |
Use Custom Options |
Add custom options to fields/messages |
Options parsed and respected |
16 |
Define RPC Service |
Define service and RPC methods in .proto |
Service compiles and stubs generated |
17 |
Generate Code in Go |
Generate Go code from .proto |
Code compiles and runs |
18 |
Generate Code in Python |
Generate Python code from .proto |
Code compiles and runs |
19 |
Use Protobuf in Unary RPC |
Send/receive Protobuf message in unary RPC |
Message transmitted correctly |
20 |
Use Protobuf in Streaming RPC |
Use Protobuf in client/server streaming |
Messages streamed correctly |
21 |
Validate Required Fields |
Use optional keyword in proto3 |
Field presence tracked |
22 |
Use Extensions (proto2) |
Define and use extensions |
Extensions parsed correctly |
23 |
Import Custom Types |
Import and use messages from other .proto files |
Imports resolved and compiled |
24 |
Handle Unknown Fields |
Receive message with unknown fields |
Unknown fields ignored |
25 |
Use Any Type |
Use google.protobuf.Any |
Type unpacked correctly |
26 |
Use Timestamp and Duration |
Use standard time types |
Time values serialized correctly |
27 |
Use Struct and Value |
Use dynamic JSON-like types |
Data parsed correctly |
28 |
Use Field Deprecation |
Mark a field as deprecated |
Compiler warns, field still usable |
29 |
JSON Mapping |
Convert Protobuf message to JSON |
JSON output matches schema |
30 |
Parse JSON to Protobuf |
Convert JSON to Protobuf |
Message populated correctly |
31 |
Use Reflection |
Inspect message structure at runtime |
Fields and types accessible |
32 |
Use REST Gateway |
Use gRPC-Gateway to expose Protobuf over HTTP |
JSON mapped to Protobuf correctly |
33 |
Use with gRPC-Web |
Use Protobuf in browser via gRPC-Web |
Messages encoded/decoded correctly |
34 |
Use Compression |
Compress Protobuf messages |
Size reduced, message valid |
35 |
Use with Interceptors |
Inspect/modify Protobuf messages in interceptor |
Interceptor sees correct message |
36 |
Use with Middleware |
Pass Protobuf messages through middleware |
Middleware processes correctly |
37 |
Use with Load Balancer |
Send Protobuf messages through load-balanced gRPC |
Messages routed and handled correctly |
38 |
Use with Retry Logic |
Retry failed Protobuf-based RPC |
Message re-sent and handled |
39 |
Use with Deadlines |
Set deadline for RPC |
Timeout enforced |
40 |
Use with Metadata |
Attach metadata to Protobuf RPC |
Metadata accessible on server |
41 |
Use with Error Handling |
Return structured error using Protobuf |
Error parsed and displayed |
42 |
Use with Status Codes |
Return gRPC status with Protobuf message |
Status and message handled correctly |
43 |
Use Custom Error Types |
Define custom error message types |
Custom errors parsed correctly |
44 |
Versioning .proto Files |
Maintain multiple versions |
Clients interoperate correctly |
45 |
Use in CI/CD Pipeline |
Compile and test .proto files in CI/CD |
Build passes with valid schema |
46 |
Lint .proto Files |
Lint for style and best practices |
Lint passes or shows actionable warnings |
47 |
Use Code Generation Plugins |
Use plugins like protoc-gen-validate |
Generated code includes validation logic |
48 |
Generate Multi-Language Bindings |
Generate bindings for multiple languages |
Code compiles and interoperates |
49 |
Use with IDE Integration |
Use IDE support for .proto files |
Syntax highlighting and autocomplete work |
50 |
Use with Schema Registry |
Store and retrieve .proto definitions |
Schema versioning and access managed |
HTTP/2 Transport - Testcases
# |
Test Case |
Description |
Expected Result |
|---|---|---|---|
1 |
Establish HTTP/2 Connection |
Initiate gRPC call over HTTP/2 |
Connection established successfully |
2 |
Multiplex Multiple Streams |
Send multiple RPCs over a single connection |
Streams handled concurrently |
3 |
Stream Prioritization |
Assign priorities to streams |
Higher priority streams processed first |
4 |
Flow Control Window Adjustment |
Adjust flow control window size |
Data flow adapts accordingly |
5 |
Header Compression |
Use HPACK to compress headers |
Reduced header size |
6 |
Binary Framing |
Use HTTP/2 binary framing for messages |
Frames parsed correctly |
7 |
Stream Reset Handling |
Reset a stream mid-communication |
Stream closed gracefully |
8 |
Connection Keepalive |
Send keepalive pings |
Connection remains active |
9 |
Connection Timeout |
Simulate idle timeout |
Connection closed after timeout |
10 |
Connection Reuse |
Reuse existing HTTP/2 connection for new RPCs |
No new TCP connection created |
11 |
Server Push Rejection |
Ensure server push is disabled |
No unsolicited responses |
12 |
Large Payload Handling |
Send large message over HTTP/2 |
Message split into frames and reassembled |
13 |
Bidirectional Streaming |
Use full-duplex communication |
Both client and server send/receive simultaneously |
14 |
Client Streaming |
Send multiple messages from client |
Server receives all messages |
15 |
Server Streaming |
Server sends multiple messages |
Client receives all messages |
16 |
Stream Cancellation |
Cancel stream from client side |
Server receives cancellation |
17 |
Stream Error Propagation |
Trigger error mid-stream |
Error propagated to client |
18 |
Max Concurrent Streams |
Exceed max concurrent stream limit |
Excess streams rejected |
19 |
Stream ID Management |
Ensure stream IDs increment correctly |
No ID reuse or collision |
20 |
Header Order Preservation |
Maintain header order |
Headers received in correct order |
21 |
Trailers Support |
Send trailers after message body |
Trailers parsed correctly |
22 |
Ping Frame Handling |
Send and receive ping frames |
RTT measured accurately |
23 |
SETTINGS Frame Exchange |
Exchange settings between client and server |
Settings acknowledged |
24 |
GOAWAY Frame Handling |
Server sends GOAWAY |
Client stops initiating new streams |
25 |
Window Update Frame Handling |
Send WINDOW_UPDATE frames |
Flow control window increased |
26 |
Frame Size Limit Enforcement |
Send frame exceeding max size |
Frame rejected or split |
27 |
Header Size Limit Enforcement |
Send large headers |
Headers rejected if too large |
28 |
Connection Preface Validation |
Validate HTTP/2 connection preface |
Invalid preface rejected |
29 |
Stream Timeout |
Simulate stream-level timeout |
Stream closed with error |
30 |
Connection Error Handling |
Trigger protocol error |
Connection closed with error |
31 |
TLS with HTTP/2 |
Use HTTP/2 over TLS |
Secure connection established |
32 |
ALPN Negotiation |
Use ALPN to negotiate HTTP/2 |
HTTP/2 selected |
33 |
Proxy Compatibility |
Use HTTP/2 through proxy |
Proxy forwards frames correctly |
34 |
Load Balancer Compatibility |
Use HTTP/2 with load balancer |
Streams routed correctly |
35 |
NAT Traversal |
Maintain HTTP/2 connection through NAT |
Connection remains stable |
36 |
IPv6 Support |
Use HTTP/2 over IPv6 |
Connection established |
37 |
IPv4 Support |
Use HTTP/2 over IPv4 |
Connection established |
38 |
Header Compression Efficiency |
Measure header compression ratio |
Compression reduces size significantly |
39 |
Stream Interleaving |
Interleave frames from multiple streams |
Frames decoded correctly |
40 |
Stream Flow Control Enforcement |
Exceed flow control window |
Data blocked until window update |
41 |
Connection-Level Flow Control |
Exceed connection-level window |
All streams blocked |
42 |
Graceful Shutdown |
Server initiates graceful shutdown |
Client completes in-flight streams |
43 |
Stream-Level Retry |
Retry failed stream |
Stream re-established |
44 |
Connection-Level Retry |
Retry after connection failure |
New connection established |
45 |
Frame Reordering Handling |
Simulate out-of-order frames |
Frames reassembled correctly |
46 |
Frame Loss Recovery |
Simulate frame loss |
Stream fails or retries |
47 |
Stream Fragmentation |
Fragment large message into multiple frames |
Message reassembled correctly |
48 |
Stream Compression |
Compress message payload |
Payload decompressed correctly |
49 |
Server Push Disabled |
Ensure server push is not used |
No unsolicited data sent |
50 |
HTTP/2 Compliance |
Validate full compliance with HTTP/2 spec |
All protocol rules followed |
Cross language support - Testcases
# |
Test Case |
Description |
Expected Result |
|---|---|---|---|
1 |
Generate Code in Go |
Generate client/server code from .proto in Go |
Code compiles and runs |
2 |
Generate Code in Java |
Generate client/server code in Java |
Code compiles and runs |
3 |
Generate Code in Python |
Generate client/server code in Python |
Code executes correctly |
4 |
Generate Code in C++ |
Generate client/server code in C++ |
Code compiles and runs |
5 |
Generate Code in C# |
Generate client/server code in C# |
Code compiles and runs |
6 |
Generate Code in Ruby |
Generate client/server code in Ruby |
Code executes correctly |
7 |
Generate Code in Node.js |
Generate client/server code in Node.js |
Code executes correctly |
8 |
Generate Code in PHP |
Generate client/server code in PHP |
Code executes correctly |
9 |
Generate Code in Kotlin |
Generate client/server code in Kotlin |
Code compiles and runs |
10 |
Generate Code in Swift |
Generate client code in Swift |
Code compiles and runs |
11 |
Interop: Go Server, Java Client |
Start server in Go, connect with Java client |
Communication successful |
12 |
Interop: Java Server, Python Client |
Start server in Java, connect with Python client |
Communication successful |
13 |
Interop: C++ Server, C# Client |
Start server in C++, connect with C# client |
Communication successful |
14 |
Interop: Node.js Server, Go Client |
Start server in Node.js, connect with Go client |
Communication successful |
15 |
Interop: Python Server, Ruby Client |
Start server in Python, connect with Ruby client |
Communication successful |
16 |
Unary RPC Across Languages |
Test unary RPC between different language pairs |
Request/response successful |
17 |
Server Streaming Across Languages |
Test server streaming RPC across languages |
Stream received correctly |
18 |
Client Streaming Across Languages |
Test client streaming RPC across languages |
Stream sent correctly |
19 |
Bidirectional Streaming Across Languages |
Test full-duplex streaming across languages |
Messages exchanged correctly |
20 |
Use Common Protobuf Schema |
Share .proto file across languages |
All languages generate consistent code |
21 |
Use Custom Options in Protobuf |
Use custom options and verify support across languages |
Options respected or ignored gracefully |
22 |
Use Enums Across Languages |
Define enums in .proto and use in all languages |
Enum values mapped correctly |
23 |
Use Maps Across Languages |
Define map fields and test serialization |
Maps handled correctly |
24 |
Use Oneof Across Languages |
Use oneof fields and test behavior |
Only one field set at a time |
25 |
Use Repeated Fields Across Languages |
Use repeated fields (arrays/lists) |
Lists handled correctly |
26 |
Use Nested Messages Across Languages |
Use nested message structures |
Nested fields parsed correctly |
27 |
Use Optional Fields Across Languages |
Use optional fields |
Optionality respected |
28 |
Use Default Values Across Languages |
Rely on default values |
Defaults applied consistently |
29 |
Use Metadata Across Languages |
Send/receive metadata |
Metadata accessible |
30 |
Use Deadlines Across Languages |
Set deadlines and timeouts |
Timeouts enforced |
31 |
Use TLS Across Languages |
Secure communication with TLS |
Connection encrypted |
32 |
Use Compression Across Languages |
Enable message compression |
Messages compressed and decompressed |
33 |
Use Interceptors Across Languages |
Add interceptors/middleware |
Interceptors invoked correctly |
34 |
Use Error Handling Across Languages |
Return and parse structured errors |
Errors handled consistently |
35 |
Use Status Codes Across Languages |
Return gRPC status codes |
Status interpreted correctly |
36 |
Use Streaming Flow Control |
Test flow control in streaming RPCs |
Flow respected across languages |
37 |
Use Authentication Across Languages |
Use token-based or mTLS authentication |
Authenticated successfully |
38 |
Use Load Balancing Across Languages |
Connect to load-balanced server |
Requests distributed correctly |
39 |
Use Retry Policies Across Languages |
Configure and test retry logic |
Retries performed as expected |
40 |
Use Reflection API |
Use gRPC reflection to discover services |
Services listed correctly |
41 |
Use Health Check API |
Use standard health check service |
Health status returned |
42 |
Use Logging Across Languages |
Log gRPC calls |
Logs generated correctly |
43 |
Use Monitoring/Tracing Tools |
Integrate with tools like OpenTelemetry |
Traces collected across languages |
44 |
Use Code Linting for .proto Files |
Lint .proto files for style |
Lint passes or shows warnings |
45 |
Use CI/CD for Multi-Language Builds |
Compile and test all language clients in CI |
Build passes for all targets |
46 |
Use Versioned APIs |
Maintain multiple versions of .proto files |
Clients interoperate correctly |
47 |
Use Language-Specific Features |
Use idiomatic constructs in each language |
Code remains idiomatic and functional |
48 |
Handle Unknown Fields |
Send unknown fields between languages |
Fields ignored gracefully |
49 |
Use Language-Specific gRPC Libraries |
Use official or community-supported libraries |
Libraries function correctly |
50 |
Validate Interop with gRPC Interop Suite |
Run gRPC interoperability test suite |
All tests pass |
streaming support - Testcases
# |
Test Case |
Description |
Expected Result |
|---|---|---|---|
1 |
Client Streaming RPC |
Client sends multiple messages to server |
Server receives all messages |
2 |
Server Streaming RPC |
Server sends multiple messages to client |
Client receives all messages |
3 |
Bidirectional Streaming RPC |
Both client and server stream messages |
Messages exchanged in real-time |
4 |
Stream Initialization |
Establish streaming connection |
Stream opens successfully |
5 |
Stream Termination |
Close stream gracefully |
Stream closes without error |
6 |
Stream Cancellation by Client |
Client cancels stream mid-way |
Server receives cancellation |
7 |
Stream Cancellation by Server |
Server cancels stream mid-way |
Client receives cancellation |
8 |
Stream Timeout |
Simulate timeout during streaming |
Stream closed with deadline exceeded |
9 |
Stream Error Propagation |
Trigger error during stream |
Error propagated to other side |
10 |
Stream Retry Logic |
Retry failed stream |
Stream re-established |
11 |
Stream Flow Control |
Respect flow control limits |
No overflow or data loss |
12 |
Stream with Large Payloads |
Send large messages in stream |
Messages split and reassembled |
13 |
Stream with Small Payloads |
Send many small messages |
All messages received |
14 |
Stream with Compression |
Enable compression for stream |
Messages compressed and decompressed |
15 |
Stream with Metadata |
Attach metadata to stream |
Metadata accessible |
16 |
Stream with Authentication |
Authenticate before streaming |
Authenticated successfully |
17 |
Stream with TLS |
Use TLS-secured stream |
Encrypted communication |
18 |
Stream with Interceptors |
Use interceptors to inspect stream |
Interceptors invoked correctly |
19 |
Stream with Logging |
Log all stream messages |
Logs show correct sequence |
20 |
Stream with Monitoring |
Monitor stream with tracing tools |
Metrics collected |
21 |
Stream with Deadline |
Set deadline for stream |
Stream ends on timeout |
22 |
Stream with Backpressure |
Simulate slow consumer |
Flow control respected |
23 |
Stream with Burst Load |
Send burst of messages |
No message loss |
24 |
Stream with Network Delay |
Simulate network latency |
Stream continues with delay |
25 |
Stream with Packet Loss |
Simulate packet loss |
Stream retries or fails gracefully |
26 |
Stream with Reconnection |
Reconnect after network drop |
Stream resumes or restarts |
27 |
Stream with Bidirectional Sync |
Sync data in both directions |
Data exchanged correctly |
28 |
Stream with Stateful Server |
Maintain state across stream messages |
State preserved |
29 |
Stream with Stateless Server |
Handle each message independently |
No state retained |
30 |
Stream with Message Ordering |
Ensure message order is preserved |
Messages received in order |
31 |
Stream with Out-of-Order Messages |
Simulate out-of-order delivery |
Messages reordered or flagged |
32 |
Stream with Duplicate Messages |
Send duplicate messages |
Duplicates handled gracefully |
33 |
Stream with Message Acknowledgment |
Acknowledge each message |
ACKs received |
34 |
Stream with Custom Headers |
Send custom headers |
Headers received correctly |
35 |
Stream with Trailers |
Send trailers after stream |
Trailers parsed correctly |
36 |
Stream with Binary Data |
Send binary payloads |
Data received intact |
37 |
Stream with JSON Payload |
Send JSON-encoded data |
Parsed correctly |
38 |
Stream with Protobuf Payload |
Use Protobuf messages |
Messages serialized/deserialized |
39 |
Stream with Error Recovery |
Recover from mid-stream error |
Stream resumes or fails gracefully |
40 |
Stream with Multi-Client Load |
Multiple clients stream simultaneously |
Server handles all streams |
41 |
Stream with Multi-Server Load |
Client streams to multiple servers |
Load balanced correctly |
42 |
Stream with Versioned APIs |
Use different versions of streaming APIs |
Compatible communication |
43 |
Stream with Rate Limiting |
Enforce rate limits on stream |
Excess messages throttled |
44 |
Stream with Quotas |
Enforce quotas on stream usage |
Limits respected |
45 |
Stream with Health Check |
Monitor stream health |
Health status reported |
46 |
Stream with Reflection |
Discover streaming methods dynamically |
Methods listed correctly |
47 |
Stream with CI/CD Integration |
Test streaming in CI pipeline |
Tests pass |
48 |
Stream with Language Interoperability |
Stream between different language clients/servers |
Messages exchanged correctly |
49 |
Stream with Mobile Client |
Stream from mobile app |
Stream stable and responsive |
50 |
Stream with Embedded Device |
Stream from IoT/embedded system |
Stream functional with constraints |
Contract first API Design - Testcases
# |
Test Case |
Description |
Expected Result |
|---|---|---|---|
1 |
Define Basic .proto File |
Create a .proto file with a simple service and message |
File compiles successfully |
2 |
Use Service Definition |
Define service with RPC methods |
Service recognized by code generator |
3 |
Use Message Definition |
Define request and response messages |
Messages compiled correctly |
4 |
Use Enum in .proto |
Define enum type in .proto |
Enum values parsed correctly |
5 |
Use Nested Messages |
Define nested message structures |
Nested fields accessible |
6 |
Use Repeated Fields |
Define repeated fields (lists) |
Lists handled correctly |
7 |
Use Optional Fields |
Use optional keyword in proto3 |
Optionality respected |
8 |
Use Oneof Fields |
Define mutually exclusive fields |
Only one field set at a time |
9 |
Use Map Fields |
Define map (key-value) fields |
Maps serialized correctly |
10 |
Use Reserved Fields |
Reserve field numbers/names |
Compiler prevents reuse |
11 |
Use Default Values |
Rely on default values |
Defaults applied correctly |
12 |
Use Custom Options |
Add custom options to messages or fields |
Options parsed or ignored gracefully |
13 |
Use Comments for Documentation |
Add comments in .proto file |
Comments appear in generated docs |
14 |
Use Import Statements |
Import types from other .proto files |
Imports resolved correctly |
15 |
Use Package Declaration |
Define package name |
Namespace applied in generated code |
16 |
Use Syntax Declaration |
Specify proto3 syntax |
Compiler uses correct version |
17 |
Generate Code in Go |
Generate Go code from .proto |
Code compiles and runs |
18 |
Generate Code in Python |
Generate Python code from .proto |
Code executes correctly |
19 |
Generate Code in Java |
Generate Java code from .proto |
Code compiles and runs |
20 |
Generate Code in C++ |
Generate C++ code from .proto |
Code compiles and runs |
21 |
Generate Code in C# |
Generate C# code from .proto |
Code compiles and runs |
22 |
Generate Code in Node.js |
Generate Node.js code from .proto |
Code executes correctly |
23 |
Validate Field Number Uniqueness |
Use unique field numbers |
Compiler accepts schema |
24 |
Detect Duplicate Field Numbers |
Use duplicate field numbers |
Compiler throws error |
25 |
Detect Missing Field Types |
Omit field type in message |
Compiler throws error |
26 |
Detect Invalid Syntax |
Use invalid syntax in .proto |
Compiler throws error |
27 |
Use Protobuf Linter |
Lint .proto file for style and best practices |
Lint passes or shows warnings |
28 |
Use Protobuf Validator Plugin |
Use protoc-gen-validate for field validation |
Validation rules enforced |
29 |
Use Versioned .proto Files |
Maintain multiple versions of API |
Clients interoperate correctly |
30 |
Use Semantic Naming |
Follow naming conventions in .proto |
Code is readable and consistent |
31 |
Use gRPC Gateway Annotations |
Add HTTP annotations for REST support |
REST endpoints generated |
32 |
Use Field Deprecation |
Mark field as deprecated |
Warning shown in generated code |
33 |
Use Field Aliases |
Rename field in code while keeping Protobuf name |
Serialization remains consistent |
34 |
Use JSON Mapping |
Convert Protobuf to JSON |
JSON matches schema |
35 |
Use Reflection API |
Enable gRPC reflection |
Services discoverable dynamically |
36 |
Use Health Check API |
Define health check service in .proto |
Health status accessible |
37 |
Use Streaming RPCs |
Define client/server/bidirectional streaming methods |
Streams function correctly |
38 |
Use Unary RPCs |
Define simple request-response methods |
RPCs function correctly |
39 |
Use Metadata in .proto |
Define metadata expectations in comments or options |
Metadata handled correctly |
40 |
Use Error Handling Schema |
Define structured error messages |
Errors parsed correctly |
41 |
Use Status Codes in .proto |
Document expected status codes |
Clients handle codes correctly |
42 |
Use CI/CD to Validate .proto |
Compile .proto in CI pipeline |
Build passes |
43 |
Use .proto in API Documentation |
Generate API docs from .proto |
Docs reflect schema accurately |
44 |
Use .proto in SDK Generation |
Generate SDKs from .proto |
SDKs consistent across languages |
45 |
Use .proto in Mock Server Generation |
Generate mock server from .proto |
Mocks simulate real behavior |
46 |
Use .proto in Test Automation |
Use .proto to drive test cases |
Tests validate contract |
47 |
Use .proto in Schema Registry |
Store .proto in central registry |
Versioning and access managed |
48 |
Use .proto in Code Review |
Review .proto for API changes |
Changes approved or flagged |
49 |
Use .proto for Backward Compatibility |
Add new fields without breaking clients |
Older clients continue to work |
50 |
Use .proto for Forward Compatibility |
Ignore unknown fields in newer messages |
New clients interoperate with old servers |
Built in authentication - Testcases
# |
Test Case |
Description |
Expected Result |
|---|---|---|---|
1 |
Enable TLS on Server |
Configure server with TLS certificate |
Secure connection established |
2 |
Enable TLS on Client |
Configure client to use TLS |
Secure connection established |
3 |
Use Self-Signed Certificate |
Use self-signed cert for TLS |
Connection established with trust override |
4 |
Use Expired Certificate |
Use expired TLS certificate |
Connection rejected |
5 |
Use Revoked Certificate |
Use revoked TLS certificate |
Connection rejected |
6 |
Use Mutual TLS |
Require client certificate |
Mutual authentication successful |
7 |
Use Invalid Client Certificate |
Present invalid client certificate |
Connection rejected |
8 |
Use Token-Based Auth |
Send bearer token in metadata |
Token validated and access granted |
9 |
Use Expired Token |
Send expired token |
Access denied |
10 |
Use Invalid Token |
Send malformed or invalid token |
Access denied |
11 |
Use OAuth2 Access Token |
Authenticate using OAuth2 token |
Token validated by server |
12 |
Use OAuth2 Refresh Token |
Refresh access token |
New token issued |
13 |
Use JWT Token |
Authenticate using JWT |
Token verified and claims extracted |
14 |
Use Token with Scopes |
Send token with specific scopes |
Access granted based on scope |
15 |
Use Token with Audience Claim |
Validate audience in JWT |
Access granted if audience matches |
16 |
Use Token with Exp Claim |
Validate expiration in JWT |
Access denied if expired |
17 |
Use Token with Issuer Claim |
Validate issuer in JWT |
Access denied if issuer mismatch |
18 |
Use Token with Signature Validation |
Validate token signature |
Access granted if valid |
19 |
Use OAuth2 with Authorization Code Flow |
Complete full OAuth2 flow |
Token issued and used |
20 |
Use OAuth2 with Client Credentials Flow |
Authenticate using client credentials |
Token issued and used |
21 |
Use OAuth2 with PKCE |
Use PKCE extension in OAuth2 flow |
Token issued securely |
22 |
Use OAuth2 with OpenID Connect |
Retrieve ID token |
Identity verified |
23 |
Use Auth Interceptor on Client |
Add interceptor to attach token |
Token sent with each request |
24 |
Use Auth Interceptor on Server |
Add interceptor to validate token |
Requests authenticated |
25 |
Use Auth Middleware |
Use middleware for authentication |
Middleware enforces auth |
26 |
Use Auth with Streaming RPC |
Authenticate before streaming |
Stream allowed if authenticated |
27 |
Use Auth with Unary RPC |
Authenticate unary RPC |
Access granted if valid |
28 |
Use Auth with Metadata |
Send token in metadata |
Metadata parsed and validated |
29 |
Use Auth with TLS and Token |
Combine TLS and token-based auth |
Dual-layer security enforced |
30 |
Use Auth with Role-Based Access Control |
Enforce RBAC using token claims |
Access granted based on role |
31 |
Use Auth with Attribute-Based Access |
Enforce ABAC using token attributes |
Access granted based on attributes |
32 |
Use Auth with Custom Claims |
Use custom claims in JWT |
Claims parsed and used |
33 |
Use Auth with Anonymous Access |
Allow unauthenticated access to some methods |
Access granted without token |
34 |
Use Auth with Method-Level Restrictions |
Restrict access to specific RPC methods |
Unauthorized methods blocked |
35 |
Use Auth with Service-Level Restrictions |
Restrict access to entire service |
Unauthorized services blocked |
36 |
Use Auth with Expired TLS Session |
Simulate expired TLS session |
Re-authentication required |
37 |
Use Auth with Token Revocation |
Revoke token and attempt access |
Access denied |
38 |
Use Auth with Token Introspection |
Validate token via introspection endpoint |
Token status confirmed |
39 |
Use Auth with External Identity Provider |
Authenticate via external IdP |
Identity verified |
40 |
Use Auth with Federated Identity |
Use federated login (e.g., Google, Azure AD) |
Access granted |
41 |
Use Auth with Multi-Factor Authentication |
Require second factor |
Access granted after MFA |
42 |
Use Auth with Rate Limiting |
Limit auth attempts |
Excess attempts blocked |
43 |
Use Auth with Logging |
Log authentication attempts |
Logs show success/failure |
44 |
Use Auth with Monitoring |
Monitor auth metrics |
Metrics collected |
45 |
Use Auth with CI/CD |
Test authentication in CI pipeline |
Tests pass |
46 |
Use Auth with Token Caching |
Cache token on client |
Token reused efficiently |
47 |
Use Auth with Token Rotation |
Rotate token periodically |
New token used seamlessly |
48 |
Use Auth with Token Expiry Notification |
Notify user before token expires |
Alert shown |
49 |
Use Auth with Secure Storage |
Store token securely on client |
Token not exposed |
50 |
Use Auth with Revocation List |
Check token against revocation list |
Revoked tokens denied |
Load balancing Retry - Testcases
# |
Test Case |
Description |
Expected Result |
|---|---|---|---|
1 |
Configure Round-Robin Load Balancer |
Use round-robin strategy for client-side load balancing |
Requests distributed evenly |
2 |
Configure Pick-First Load Balancer |
Use pick-first strategy |
All requests go to first available server |
3 |
Use Custom Load Balancer |
Implement and use custom load balancing logic |
Custom logic applied |
4 |
Use DNS-Based Load Balancing |
Resolve multiple IPs via DNS |
Requests distributed among resolved addresses |
5 |
Use xDS Load Balancer |
Use xDS-based dynamic configuration |
Load balancing controlled by external system |
6 |
Load Balance Across 2 Servers |
Distribute requests between 2 servers |
Both servers receive traffic |
7 |
Load Balance Across 3+ Servers |
Distribute requests among 3 or more servers |
Traffic evenly distributed |
8 |
Load Balance with Server Health Check |
Skip unhealthy servers |
Only healthy servers used |
9 |
Load Balance with Server Weighting |
Assign weights to servers |
Traffic follows weight distribution |
10 |
Load Balance with Server Failover |
Failover to backup server on failure |
Requests rerouted automatically |
11 |
Load Balance with Server Restart |
Restart one server during load |
Requests rerouted temporarily |
12 |
Load Balance with Server Timeout |
Simulate server timeout |
Retry or reroute triggered |
13 |
Load Balance with Server Crash |
Simulate server crash |
Requests rerouted |
14 |
Load Balance with Network Partition |
Simulate network partition |
Client switches to reachable server |
15 |
Load Balance with TLS |
Use TLS-secured connections |
Secure load balancing |
16 |
Load Balance with Streaming RPC |
Stream data across balanced servers |
Stream handled correctly |
17 |
Load Balance with Unary RPC |
Send unary requests |
Requests distributed |
18 |
Load Balance with Metadata |
Send metadata with requests |
Metadata preserved |
19 |
Load Balance with Retry Enabled |
Enable retry policy |
Failed requests retried |
20 |
Retry on Unavailable Error |
Retry when server returns UNAVAILABLE |
Request retried automatically |
21 |
Retry on Deadline Exceeded |
Retry when deadline exceeded |
Retry triggered |
22 |
Retry on Internal Error |
Retry on INTERNAL error |
Retry triggered |
23 |
Retry on Resource Exhausted |
Retry on RESOURCE_EXHAUSTED |
Retry triggered or delayed |
24 |
Retry with Max Attempts |
Set max retry attempts |
Retries stop after limit |
25 |
Retry with Backoff |
Use exponential backoff between retries |
Delay increases with each retry |
26 |
Retry with Jitter |
Add jitter to retry delay |
Retry intervals randomized |
27 |
Retry with Per-Method Policy |
Apply retry policy to specific RPCs |
Only selected methods retried |
28 |
Retry with Global Policy |
Apply retry policy to all RPCs |
All eligible methods retried |
29 |
Retry with Streaming RPC |
Retry streaming RPC |
Stream re-established |
30 |
Retry with Unary RPC |
Retry unary RPC |
Request retried |
31 |
Retry with Token-Based Auth |
Retry with token in metadata |
Token preserved across retries |
32 |
Retry with TLS |
Retry over secure connection |
TLS session reused or re-established |
33 |
Retry with Load Balancer Change |
Retry after switching load balancer |
Retry succeeds with new server |
34 |
Retry with Server Restart |
Retry after server restart |
Request retried successfully |
35 |
Retry with Server Crash |
Retry after crash |
Request rerouted |
36 |
Retry with Network Drop |
Retry after network failure |
Request retried after reconnect |
37 |
Retry with Deadline |
Retry within deadline |
Retry stops if deadline exceeded |
38 |
Retry with Cancelled Context |
Retry with cancelled context |
Retry not attempted |
39 |
Retry with Custom Error Codes |
Retry on custom-defined error codes |
Retry triggered as configured |
40 |
Retry with Rate Limiting |
Retry under rate-limited conditions |
Retry delayed or blocked |
41 |
Retry with Logging |
Log retry attempts |
Logs show retry sequence |
42 |
Retry with Monitoring |
Monitor retry metrics |
Retry count and latency tracked |
43 |
Retry with Circuit Breaker |
Use circuit breaker to block retries temporarily |
Retry paused during open state |
44 |
Retry with Retry Budget |
Limit retries using retry budget |
Retry stops when budget exhausted |
45 |
Retry with Client Interceptor |
Use interceptor to manage retries |
Interceptor logic applied |
46 |
Retry with Server Interceptor |
Server logs retry attempts |
Retry attempts visible on server |
47 |
Retry with CI/CD Pipeline |
Test retry logic in CI |
Tests pass |
48 |
Retry with Multi-Region Servers |
Retry across regions |
Request rerouted to available region |
49 |
Retry with Load Balancer Failover |
Retry after load balancer failure |
Request rerouted |
50 |
Retry with Retry Token Bucket |
Use token bucket to limit retries |
Retry throttled based on token availability |
Pluggable Architecture - Testcases
# |
Test Case |
Description |
Expected Result |
|---|---|---|---|
1 |
Add Unary Client Interceptor |
Attach interceptor to client unary calls |
Interceptor invoked before/after call |
2 |
Add Unary Server Interceptor |
Attach interceptor to server unary calls |
Interceptor invoked before/after handler |
3 |
Add Streaming Client Interceptor |
Attach interceptor to client streaming calls |
Interceptor invoked on stream events |
4 |
Add Streaming Server Interceptor |
Attach interceptor to server streaming calls |
Interceptor invoked on stream events |
5 |
Chain Multiple Interceptors |
Use multiple interceptors in sequence |
All interceptors executed in order |
6 |
Use Interceptor for Logging |
Log request and response metadata |
Logs contain expected data |
7 |
Use Interceptor for Authentication |
Validate token in interceptor |
Access granted or denied |
8 |
Use Interceptor for Metrics |
Collect metrics like latency, error rate |
Metrics recorded correctly |
9 |
Use Interceptor for Tracing |
Add tracing spans to RPC calls |
Traces visible in monitoring tool |
10 |
Use Interceptor for Retry Logic |
Implement retry in client interceptor |
Failed calls retried |
11 |
Use Interceptor for Rate Limiting |
Enforce rate limits per user |
Excess requests blocked |
12 |
Use Interceptor for Request Validation |
Validate request payload before processing |
Invalid requests rejected |
13 |
Use Interceptor for Response Transformation |
Modify response before sending to client |
Response altered as expected |
14 |
Use Interceptor for Header Injection |
Add custom headers to outgoing requests |
Headers visible on server |
15 |
Use Interceptor for Header Extraction |
Read headers from incoming requests |
Headers logged or used |
16 |
Use Interceptor for Context Injection |
Add values to context |
Context accessible in handler |
17 |
Use Interceptor for Panic Recovery |
Catch and log panics in server handler |
Server does not crash |
18 |
Use Interceptor for Audit Logging |
Log sensitive operations |
Audit trail created |
19 |
Use Interceptor for IP Whitelisting |
Allow only specific IPs |
Unauthorized IPs blocked |
20 |
Use Interceptor for Geo-Blocking |
Block requests from certain regions |
Requests denied based on location |
21 |
Use Interceptor for A/B Testing |
Route traffic based on experiment group |
Traffic split correctly |
22 |
Use Interceptor for Feature Flags |
Enable/disable features dynamically |
Behavior changes based on flags |
23 |
Use Interceptor for Caching |
Cache responses for idempotent requests |
Cached response returned |
24 |
Use Interceptor for Request Enrichment |
Add additional data to request |
Enriched request processed |
25 |
Use Interceptor for Request Deduplication |
Detect and drop duplicate requests |
Only one request processed |
26 |
Use Interceptor for Request Throttling |
Throttle high-frequency requests |
Rate limited responses |
27 |
Use Interceptor for Custom Error Handling |
Customize error responses |
Errors formatted consistently |
28 |
Use Interceptor for Locale Detection |
Detect user locale from headers |
Locale used in response |
29 |
Use Interceptor for Session Management |
Track session state |
Session data persisted |
30 |
Use Interceptor for Access Logging |
Log access details (method, IP, duration) |
Logs contain access info |
31 |
Use Interceptor for Request ID Injection |
Generate and attach request ID |
ID visible in logs and responses |
32 |
Use Interceptor for Debug Mode |
Enable debug logging for specific users |
Debug logs generated |
33 |
Use Interceptor for Multi-Tenancy |
Extract tenant ID from metadata |
Tenant context applied |
34 |
Use Interceptor for Quota Enforcement |
Enforce usage quotas |
Quota exceeded error returned |
35 |
Use Interceptor for Custom Authentication |
Plug in custom auth logic |
Authenticated based on custom rules |
36 |
Use Interceptor for Token Refresh |
Refresh expired tokens |
New token issued |
37 |
Use Interceptor for Request Replay |
Replay captured requests for testing |
Requests replayed successfully |
38 |
Use Interceptor for Canary Releases |
Route traffic to canary version |
Canary receives expected traffic |
39 |
Use Interceptor for Circuit Breaking |
Block calls to failing services |
Circuit opened and traffic blocked |
40 |
Use Interceptor for Service Discovery |
Dynamically resolve service endpoints |
Requests routed correctly |
41 |
Use Interceptor for Request Timeout |
Enforce custom timeout policy |
Requests cancelled after timeout |
42 |
Use Interceptor for Request Size Limit |
Reject large requests |
Error returned for oversized payloads |
43 |
Use Interceptor for Response Compression |
Compress responses based on client headers |
Compressed response sent |
44 |
Use Interceptor for Request Decompression |
Decompress incoming requests |
Request processed correctly |
45 |
Use Interceptor for Protocol Translation |
Translate between Protobuf and JSON |
Request/response converted |
46 |
Use Interceptor for Legacy Support |
Adapt legacy clients to new API |
Compatibility maintained |
47 |
Use Interceptor for Schema Validation |
Validate Protobuf schema at runtime |
Invalid messages rejected |
48 |
Use Interceptor for Request Routing |
Route requests to different handlers |
Routing logic applied |
49 |
Use Interceptor for Custom Metrics |
Record custom business metrics |
Metrics visible in dashboard |
50 |
Use Interceptor for Testing Hooks |
Inject test behavior during development |
Test hooks executed |
Efficient binary format - Testcases
# |
Test Case |
Description |
Expected Result |
|---|---|---|---|
1 |
Serialize Simple Message |
Serialize a basic Protobuf message |
Output is compact binary |
2 |
Deserialize Simple Message |
Deserialize binary data into message |
Fields populated correctly |
3 |
Compare Size with JSON |
Compare Protobuf and JSON message sizes |
Protobuf is smaller |
4 |
Compare Size with XML |
Compare Protobuf and XML message sizes |
Protobuf is significantly smaller |
5 |
Measure Serialization Speed |
Benchmark Protobuf serialization |
Faster than JSON/XML |
6 |
Measure Deserialization Speed |
Benchmark Protobuf deserialization |
Faster than JSON/XML |
7 |
Use Nested Messages |
Serialize nested Protobuf messages |
Compact and efficient |
8 |
Use Repeated Fields |
Serialize repeated fields |
Efficient encoding |
9 |
Use Oneof Fields |
Serialize mutually exclusive fields |
Only one field encoded |
10 |
Use Map Fields |
Serialize map fields |
Efficient key-value encoding |
11 |
Use Enum Fields |
Serialize enums |
Encoded as integers |
12 |
Use Optional Fields |
Omit optional fields |
Not included in binary |
13 |
Use Default Values |
Skip default values in serialization |
Not encoded, saving space |
14 |
Use Packed Repeated Fields |
Use packed encoding for repeated primitives |
More compact binary |
15 |
Use Field Number Optimization |
Use small field numbers |
Smaller encoded size |
16 |
Use Field Type Optimization |
Use efficient field types (e.g., int32 vs string) |
Smaller binary output |
17 |
Use Varint Encoding |
Encode integers using varint |
Small numbers use fewer bytes |
18 |
Use ZigZag Encoding |
Encode signed integers efficiently |
Smaller size for negative numbers |
19 |
Use Fixed32/Fixed64 Types |
Use fixed-size types |
Predictable size |
20 |
Use Float/Double Types |
Serialize floating-point numbers |
Compact binary representation |
21 |
Use Bytes Field |
Serialize raw binary data |
Efficiently encoded |
22 |
Use Timestamp Field |
Serialize google.protobuf.Timestamp |
Compact time encoding |
23 |
Use Duration Field |
Serialize google.protobuf.Duration |
Efficient duration encoding |
24 |
Use Struct Field |
Serialize dynamic JSON-like structure |
Efficient binary format |
25 |
Use Any Field |
Serialize dynamic message types |
Type and value encoded compactly |
26 |
Use Compression with Protobuf |
Compress Protobuf messages |
Further size reduction |
27 |
Use Streaming with Protobuf |
Stream Protobuf messages |
Efficient real-time transmission |
28 |
Use Protobuf in Low-Bandwidth Network |
Transmit over constrained network |
Minimal bandwidth usage |
29 |
Use Protobuf in IoT Device |
Use on resource-constrained device |
Low memory and CPU usage |
30 |
Use Protobuf in Mobile App |
Use in mobile client |
Fast and efficient messaging |
31 |
Use Protobuf in Embedded System |
Use in embedded firmware |
Compact binary fits memory constraints |
32 |
Use Protobuf in Real-Time System |
Use in latency-sensitive application |
Low serialization overhead |
33 |
Use Protobuf in High-Volume System |
Handle large message throughput |
Efficient processing |
34 |
Use Protobuf with File Transfer |
Encode file metadata |
Compact and fast |
35 |
Use Protobuf with Image Metadata |
Encode image tags and properties |
Efficient binary format |
36 |
Use Protobuf with Sensor Data |
Encode time-series sensor readings |
Compact and fast |
37 |
Use Protobuf with Financial Data |
Encode transactions and prices |
High precision, low size |
38 |
Use Protobuf with Logs |
Encode structured logs |
Efficient storage |
39 |
Use Protobuf with Telemetry |
Encode metrics and telemetry data |
Low overhead |
40 |
Use Protobuf with Chat Messages |
Encode chat messages |
Fast and small payloads |
41 |
Use Protobuf with Notifications |
Encode push notifications |
Efficient delivery |
42 |
Use Protobuf with Video Metadata |
Encode video stream metadata |
Compact and fast |
43 |
Use Protobuf with Audio Metadata |
Encode audio stream metadata |
Efficient encoding |
44 |
Use Protobuf with Game State |
Encode multiplayer game state |
Real-time performance |
45 |
Use Protobuf with Blockchain Data |
Encode blocks and transactions |
Compact and verifiable |
46 |
Use Protobuf with Machine Learning Models |
Encode model metadata and configs |
Efficient model serving |
47 |
Use Protobuf with Health Records |
Encode patient data securely and compactly |
HIPAA-compliant and efficient |
48 |
Use Protobuf with Configuration Files |
Encode app configs |
Small and portable |
49 |
Use Protobuf with API Gateway |
Transmit messages through gateway |
Low latency and size |
50 |
Use Protobuf with CDN |
Distribute Protobuf messages via CDN |
Fast and efficient delivery |
Error handling status codes - Testcases
# |
Test Case |
Description |
Expected Result |
|---|---|---|---|
1 |
Return OK Status |
Return successful response |
Status code OK (0) |
2 |
Return CANCELLED Status |
Simulate client-side cancellation |
Status code CANCELLED (1) |
3 |
Return UNKNOWN Status |
Return unknown error |
Status code UNKNOWN (2) |
4 |
Return INVALID_ARGUMENT Status |
Send invalid input |
Status code INVALID_ARGUMENT (3) |
5 |
Return DEADLINE_EXCEEDED Status |
Simulate timeout |
Status code DEADLINE_EXCEEDED (4) |
6 |
Return NOT_FOUND Status |
Request non-existent resource |
Status code NOT_FOUND (5) |
7 |
Return ALREADY_EXISTS Status |
Attempt to create duplicate resource |
Status code ALREADY_EXISTS (6) |
8 |
Return PERMISSION_DENIED Status |
Access resource without permission |
Status code PERMISSION_DENIED (7) |
9 |
Return RESOURCE_EXHAUSTED Status |
Exceed quota or limit |
Status code RESOURCE_EXHAUSTED (8) |
10 |
Return FAILED_PRECONDITION Status |
Violate precondition |
Status code FAILED_PRECONDITION (9) |
11 |
Return ABORTED Status |
Simulate aborted operation |
Status code ABORTED (10) |
12 |
Return OUT_OF_RANGE Status |
Send out-of-range value |
Status code OUT_OF_RANGE (11) |
13 |
Return UNIMPLEMENTED Status |
Call unimplemented method |
Status code UNIMPLEMENTED (12) |
14 |
Return INTERNAL Status |
Trigger internal server error |
Status code INTERNAL (13) |
15 |
Return UNAVAILABLE Status |
Simulate server unavailability |
Status code UNAVAILABLE (14) |
16 |
Return DATA_LOSS Status |
Simulate data corruption |
Status code DATA_LOSS (15) |
17 |
Return UNAUTHENTICATED Status |
Access without valid credentials |
Status code UNAUTHENTICATED (16) |
18 |
Include Error Message |
Return error with descriptive message |
Message shown in client |
19 |
Include Error Details |
Attach structured error details |
Details parsed by client |
20 |
Include Error Metadata |
Attach metadata to error |
Metadata accessible |
21 |
Handle Error in Unary RPC |
Return error in unary RPC |
Client receives status and message |
22 |
Handle Error in Streaming RPC |
Return error mid-stream |
Stream terminated with error |
23 |
Retry on UNAVAILABLE |
Retry when server is unavailable |
Retry logic triggered |
24 |
Do Not Retry on INVALID_ARGUMENT |
Avoid retry on client-side error |
Retry skipped |
25 |
Log Error on Server |
Log error details |
Logs contain status and message |
26 |
Log Error on Client |
Log received error |
Client logs contain status |
27 |
Map Internal Exception to gRPC Status |
Convert internal error to gRPC status |
Correct status returned |
28 |
Use Custom Error Codes |
Define application-specific error codes |
Codes included in metadata |
29 |
Use Custom Error Messages |
Return localized or user-friendly messages |
Message shown to user |
30 |
Use Error Interceptor |
Intercept and modify error responses |
Custom error formatting applied |
31 |
Use Error Wrapping |
Wrap internal errors with context |
Full error trace preserved |
32 |
Use Error Translation Layer |
Translate internal errors to gRPC status |
Consistent error mapping |
33 |
Use Error Metrics |
Track error rates |
Metrics collected |
34 |
Use Error Alerts |
Trigger alert on critical errors |
Alert sent |
35 |
Use Error Retry Budget |
Limit retries on repeated errors |
Retry throttled |
36 |
Use Error Rate Limiting |
Block requests after error threshold |
Rate limit enforced |
37 |
Use Error Circuit Breaker |
Open circuit on repeated failures |
Requests blocked temporarily |
38 |
Use Error in Health Check |
Return error in health check RPC |
Health status marked as unhealthy |
39 |
Use Error in Reflection API |
Simulate error in reflection |
Error returned with status |
40 |
Use Error in Auth Interceptor |
Deny access in interceptor |
UNAUTHENTICATED returned |
41 |
Use Error in Validation Interceptor |
Reject invalid request |
INVALID_ARGUMENT returned |
42 |
Use Error in Rate Limiting Interceptor |
Block excessive requests |
RESOURCE_EXHAUSTED returned |
43 |
Use Error in Streaming Flow Control |
Exceed flow control window |
INTERNAL or UNAVAILABLE returned |
44 |
Use Error in Deadline Enforcement |
Exceed deadline |
DEADLINE_EXCEEDED returned |
45 |
Use Error in Token Expiry |
Use expired token |
UNAUTHENTICATED returned |
46 |
Use Error in Permission Check |
Access forbidden resource |
PERMISSION_DENIED returned |
47 |
Use Error in Quota Enforcement |
Exceed usage quota |
RESOURCE_EXHAUSTED returned |
48 |
Use Error in Feature Flag Check |
Access disabled feature |
FAILED_PRECONDITION returned |
49 |
Use Error in Multi-Tenant Context |
Access resource from wrong tenant |
PERMISSION_DENIED returned |
50 |
Use Error in Legacy API Call |
Call deprecated or removed method |
UNIMPLEMENTED returned |
Reference links