Cluster Serving FAQ#

General Debug Guide#

You could use following guide to debug if serving is not working properly.

Check if Cluster Serving environment is ready#

Run following commands in terminal

echo $FLINK_HOME
echo $REDIS_HOME

the output directory

/path/to/flink-version
/path/to/redis-version

should be displayed, otherwise, go to Programming Guide Installation section.

Check if Flink Cluster is working#

Run following commands in terminal

netstat -tnlp

output like following should be displayed, 6123,8081 is Flink default port usage.

tcp6       0      0 :::6123                 :::*                    LISTEN      xxxxx/java
tcp6       0      0 :::8081                 :::*                    LISTEN      xxxxx/java

if not, run $FLINK_HOME/bin/start-cluster.sh to start Flink cluster.

After that, check Flink log in $FLINK_HOME/log/, check the log file of flink-xxx-standalone-xxx.log and flink-xxx-taskexecutor-xxx.log to make sure there is no error.

If the port could not bind in this step, kill the program which use the port, and $FLINK_HOME/bin/stop-cluster.sh && $FLINK_HOME/bin/start-cluster.sh to restart Flink cluster.

Check if Cluster Serving is running#

$FLINK_HOME/bin/flink list

output of Cluster Serving job information should be displayed, if not, go to Programming Guide Launching Service section to make sure you call cluster-serving-start correctly.

Troubleshooting#

Duplicate registration of device factory for type XLA_CPU with the same priority 50

This error is caused by Flink ClassLoader. Please put cluster serving related jars into ${FLINK_HOME}/lib.
servable Manager config dir not exist

Check if servables.yaml exists in current directory. If not, download from github.

Still, I get no result#

If you still get empty result, raise issue here and post the output/log of your serving job.