Configure client log settings for SDKs - ApsaraMQ for RocketMQ

ApsaraMQ for RocketMQ SDKs generate client logs that record runtime events and exceptions. Use these logs to troubleshoot issues during client operation.

Default log file paths

The following table lists the default log file path for each SDK language. {$HOME} is the root directory of the application that you started.

Language	Default path
Java	`{$HOME}/logs/rocketmq/rocketmq-client.log`
C++	`{$HOME}/logs/rocketmq/client.log`
C#	`{$HOME}/logs/rocketmq/rocketmq-client.log`
Go	`{$HOME}/logs/rocketmq/rocketmq_client_go.log`

Log parameters

After the client starts, it creates a log file based on default settings. The Java and Go SDKs support custom log parameters. The C++ and C# SDKs do not support custom log configuration.

Java

All Java log parameters are set through JVM system properties (-D flags).

Parameter	Description	Default	Valid values
`rocketmq.log.level`	Log verbosity level.	`INFO`	`ERROR`, `WARN`, `INFO`, `DEBUG`
`rocketmq.log.root`	Root directory for log output.	`{$HOME}/logs/rocketmq`	Any local directory with write permissions.
`rocketmq.log.file.maxIndex`	Maximum number of log files to retain. Each log file has a fixed maximum size of 64 MB.	`10`	`1`--`100`. Values outside this range or in an invalid format fall back to the default.

Note

Make sure that the application process has write permissions on the specified log directory. Otherwise, logs cannot be printed.

Go

Go log parameters are set through environment variables.

Parameter	Description	Default	Valid values
`rocketmq.client.logLevel`	Log verbosity level.	`INFO`	`ERROR`, `WARN`, `INFO`, `DEBUG`
`rocketmq.client.logRoot`	Root directory for log output.	`{$HOME}/logs/rocketmq`	Any local directory with write permissions.
`rocketmq.client.logFileName`	Log file name.	`rocketmq_client_go.log`	Any valid file name.
`rocketmq.log.file.maxIndex`	Maximum number of log files to retain.	`10`	`1`--`100`
`rocketmq.client.logFileMaxSize`	Maximum size of each log file.	`1 GB`	--

Note

Make sure that the application process has write permissions on the specified log directory. Otherwise, logs cannot be printed.

Configure logging

Java

In the startup script or IDE VM options, pass -D flags to set log parameters.

Set the log level to INFO:

java -Drocketmq.log.level=INFO -jar foobar.jar

Set a custom log directory and increase file retention:

java -Drocketmq.log.level=WARN \
     -Drocketmq.log.root=/var/log/myapp/rocketmq \
     -Drocketmq.log.file.maxIndex=20 \
     -jar foobar.jar

Go

The Go SDK supports two configuration methods:

Static configuration -- Set environment variables before starting the client.
Dynamic configuration -- Set environment variables in code and call ResetLogger() to apply changes at runtime.

Dynamic configuration (change at runtime):

os.Setenv("rocketmq.client.logLevel", "WARN")
rmq_client.ResetLogger()