|Pivotal Greenplum (GPDB)||4.3.x|
You may see several messages in the Master or Segment log files with the below message:
"GetSnapshotData timed out waiting for Writer to set the shared snapshot"
This is related to the Query Dispatch (QD) process, not getting a response within a specified time period. This may be related to a high load on the cluster and the system is too busy. The QD update snapshot is too slow and then gives this message. This message is a "LOG" level message, the reader gang logs this message when it takes too long to sync with the writer gang (longer than 1 sec).
The parameter gp_interconnect_setup_timeout is set to 60 seconds as the default. Increasing this parameter may help with alleviating this log message in the log file if you are having a high load on your cluster. To set the parameter, please follow the below steps:
gpconfig -c gp_interconnect_setup_timeout -v 120 -m 120
You will then need to restart the DB for this parameter to take an effect: