Default settings and options

Configure default settings

You can efficiently process messages by configuring publish and receive (pull) settings.

Publish settings

Item	Description
DelayThreshold	Sends publish requests at defined intervals - Default: 100ms
CountThreshold	Sends messages in batch when the specified count is reached - Default: 100
NumGoroutines	Limits the number of concurrently running goroutines - Default: 2 - Max: 10
Timeout	Timeout duration for publish requests - Default: 60s
FlowControlSettings	Controls the publish rate through flow control settings

Receive settings

Item	Description
NumGoroutines	Limits the number of concurrently running goroutines - Default: 2 - Max: 10
FlowControlSettings	Controls the receive rate through flow control settings

Flow control settings

Item	Description
MaxOutstandingMessages	Maximum number of messages that can be held in the internal buffer - Default: 1000
MaxOutstandingBytes	Maximum size of messages that can be held in the internal buffer - Default: 1G
LimitExceededBehavior	Behavior when the threshold is exceeded • SignalError: Returns an error • Block (Default): Waits until request can proceed without exceeding limits  ⚠️ Useful in batch processing scenarios where individual request latency is not critical • Ignore: Disables flow control

Retry

When gRPC calls return specific error codes, retry attempts are made based on configured retry options. The default retry codes and settings per API are listed below.

Retry error status codes

Refer to gRPC status code documentation for more information.

Code	Description
CANCELLED	Call was cancelled (usually by the client)
UNKNOWN	Unknown error, possibly due to unexpected status from a different address Also occurs when the API does not return specific error info
DEADLINE_EXCEEDED	Deadline expired before the call completed
NOT_FOUND	Requested entity not found
RESOURCE_EXHAUSTED	Resource quota exceeded or system storage full
ABORTED	Operation aborted due to concurrency conflict (e.g., failed sequencer check)
INTERNAL	Internal server error
UNAVAILABLE	Service is currently unavailable

Retry configuration options

Item	Description
Initial	Initial delay before first retry - Adjusted by Multiplier
Multiplier	Next retry delay = previous retry delay × Multiplier
Max	Maximum retry delay ⚠️ Multiplier cannot increase delay beyond this limit

Publisher retry default setting

API	Retry code	Description	Retry setting
create topic	14	UNAVAILABLE	• Initial: 100ms • Multiplier: 1.3 • Max: 60s
get topic	14	UNAVAILABLE	-
list topics	14	UNAVAILABLE	-
list topic subscriptions	14	UNAVAILABLE	-
update topic	14	UNAVAILABLE	-
delete topic	14	UNAVAILABLE	-
publish	1	CANCELLED	-
	4	DEADLINE_EXCEEDED	-
	8	RESOURCE_EXHAUSTED	-
	13	INTERNAL	-
	14	UNAVAILABLE	-

Subscriber retry default setting

API	Retry code	Description	Retry setting
create subscription	14	UNAVAILABLE	• Initial: 100ms • Multiplier: 1.3 • Max: 60s
get subscription	14	UNAVAILABLE	-
list subscriptions	14	UNAVAILABLE	-
seek	14	UNAVAILABLE	-
update subscription	14	UNAVAILABLE	-
delete subscription	14	UNAVAILABLE	-
modify ack deadline	14	UNAVAILABLE	-
acknowledge	14	UNAVAILABLE	-
pull	14	UNAVAILABLE	-
streaming pull	4	DEADLINE_EXCEEDED	-
	8	RESOURCE_EXHAUSTED	-
	13	INTERNAL	-
	14	UNAVAILABLE	-

Example: Custom retry configuration

cfg := &pubsub.ClientConfig{
   PublisherCallOptions: &api.PublisherCallOptions{
      Publish: []option.CallOption{
         option.WithRetryOptions(
            option.WithCodes(codes.ResourceExhausted),
            option.WithBackoff(option.Backoff{
               Initial:    100 * time.Millisecond,
               Max:        30000 * time.Millisecond,
               Multiplier: 1.20,
            })),
      },
   },
   SubscriberCallOptions: &api.SubscriberCallOptions{
      StreamingPull: []option.CallOption{
         option.WithRetryOptions(
            option.WithCodes(codes.ResourceExhausted),
            option.WithBackoff(option.Backoff{
               Initial:    100 * time.Millisecond,
               Max:        60000 * time.Millisecond,
               Multiplier: 1.30,
            })),
      },
   },
}
client, err := NewClientWithConfig(ctx, domainID, projectID, cfg, opts...)

Logging

You can record statistical logs of request and response results (success/failure) from Publish and StreamingPull operations.

• When a time interval is configured, the number of successful and failed publish and pull attempts is logged periodically.
• To view logs, the logging level must be set to info or higher.

The logger supports the following configuration options:

Item	Description
Level	Log level - Default: Panic
Output	Log output destination - Default: os.Stdout
StatLogInterval	Interval at which logs are written

Logging example

conf := &ClientConfig{
    LogOptions: &LogOptions{
        Level: "info",
        Output: os.Stdout,
        StatLogInterval: 1 * time.Second
    }
}
client, err := NewClientWithConfig(ctx, domainID, projectID, conf, opts...)