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How to configure gremlinPool in Db2 Graph to prevent pod restart when excuting long-running queries

How To


On CP4D, the default value of gremlinPool is not sufficient for long-running queries and the health-check code that automatically runs against the pod.

When the long running loop query is running, THE value for gremlinPool is not sufficient to continue your query and respond to the health checks. When the health checks are not responded to in a timely manner this causes the deployment to believe they are unhealthy and thus terminates the pod and restarts it. This causes the restart of the pod.

To prevent this issue, you are recommended to set gremlinPool to 8.

In the CP4D 4.5.0 release, the default value for gremlinPool is increased, so this issue is resolved.


See the sample steps as below:
Note: c-db2ucluster-sample-graph-57849d4668-vszhj is the pod name for the Db2 Graph server in the test.
# oc -n <name space> exec -it c-db2ucluster-sample-graph-57849d4668-vszhj sh
kubectl exec [POD] [COMMAND] is DEPRECATED and will be removed in a future version. Use kubectl exec [POD] -- [COMMAND] instead.
sh-4.4$ pwd
sh-4.4$ ls -al
total 68
drwxr-xr-x.  2 gremlin gremlin 4096 Jul 21 06:46 .
drwxr-xr-x. 12 gremlin gremlin 4096 Jul  1 10:48 ..
-rw-r--r--.  1 gremlin gremlin  528 Jun 30 17:13 db2graph-internal.yaml
-rw-r--r--.  1 gremlin gremlin  468 Jul  1 07:52 db2graph-server.yaml
-rw-r--r--.  1 gremlin gremlin    0 Jan 28 06:58 db2.groovy
-rw-r--r--.  1 gremlin gremlin    0 Jun 30 17:13 .gremlin_groovy_history
-rw-r--r--.  1 gremlin gremlin    4 Jul  1 10:49
-rw-r--r--.  1 gremlin gremlin  926 Jul  1 10:48 gremlin-server.conf
-rw-r--r--.  1 gremlin gremlin 4167 Jul  1 10:48 gremlin-server.yaml
-rw-r--r--.  1 gremlin gremlin 1639 Jun 30 17:13 remote-secure.yaml
# vi gremlin-server.yaml, append a line "gremlinPool: 8" to it, save the file
sh-4.4$ tail gremlin-server.yaml
  trustStore: /db2graph/ssl/graph.jks,
  trustStorePassword: 769e8e98-f530-4788-aca2-241b10128c96,
authentication: {
  config: {
    credentialsDb: /db2graph/credentials/
gremlinPool: 8
# then restart Db2 graph server:
sh-4.4$ manage restart
Db2GRAPH-1000I The Db2 Graph web server is stopped.
Stopping the Db2 Graph server...
Db2GRAPH-1000I The Db2 Graph server is stopped.
Starting the Db2 Graph server...
Db2GRAPH-1000I The Db2 Graph server is running.
Starting the Db2 Graph web server...
Db2GRAPH-1000I The Db2 Graph web server is running.

Document Location


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Product Synonym

CP4D; Db2 Graph;

Document Information

Modified date:
21 July 2022