How to specify ZK instance log configuration

[dalbani]

The ZK operator generates a ConfigMap containing several items:

• zoo.cfg
• log4j.properties
• log4j-quiet.properties
• env.sh

And these files get copied to the /data/conf directory which is used by ZooKeeper if I'm not mistaken.
I would like to configure the ZooKeeper instances to use log4j-quiet.properties instead of log4j.properties.
How can I do that? Given the fact the ConfigMap gets overwritten at the reconciliation phase by the way.

[anishakj]

Are you changing the log configurations at the time of fresh installation or later?

[dalbani]

Well, I don't think it makes much of a difference AFAIK.
Because the function that creates the ConfigMap produces the same result when the ConfigMap gets created or overwritten: https://github.com/pravega/zookeeper-operator/blob/master/pkg/controller/zookeepercluster/zookeepercluster_controller.go#L447.
So I don't see how I can tweak the ConfigMap at any point.

[anishakj]

Yes you are correct. At the time of restart also, we are copying the log4j-quiet.proerties. https://github.com/pravega/zookeeper-operator/blob/master/docker/bin/zookeeperStart.sh#L159

[dalbani]

If only I could tell ZooKeeper to use log4j-quiet.properties instead of log4j.properties, that would be enough for me.
But I haven't been able to find a way to do it. For example via an environment variable.
Would you know another way by any chance?

[anishakj]

@dalbani If i understood correctly, requirement to set log level to ERROR, rather than INFO. But currently log4j.appender.CONSOLE.Threshold is set as INFO by default. If we want to make this configurable, we have to introduce new variable in spec, and set the log4j.properties accordingly.

[anishakj]

@dalbani Could you please confirm if above is the requirement

[dalbani]

@anishakj
Well, being able to provide one's own log4j.properties definition would probably be best, I suppose.
But being able to set the global log level is also fine for me.
Actually, I was wondering if it's not already possible via:

apiVersion: zookeeper.pravega.io/v1beta1
kind: ZookeeperCluster
spec:
  ...
  pod:
    ...
    env:
      - name: ZOO_LOG4J_PROP
        value: 'ERROR,CONSOLE'

Based on the code at https://github.com/apache/zookeeper/blob/master/bin/zkEnv.sh#L73.

(In my case, as a ZooKeeper user via the Solr operator, I'd still have to figure out how to pass this env information from the SolrCloud CR definition to the ZookeeperCluster CR definition. But that's another discussion.)

[anishakj]

@anishakj
Well, being able to provide one's own log4j.properties definition would probably be best, I suppose.
But being able to set the global log level is also fine for me.
Actually, I was wondering if it's not already possible via:

apiVersion: zookeeper.pravega.io/v1beta1
kind: ZookeeperCluster
spec:
  ...
  pod:
    ...
    env:
      - name: ZOO_LOG4J_PROP
        value: 'ERROR,CONSOLE'

Based on the code at https://github.com/apache/zookeeper/blob/master/bin/zkEnv.sh#L73.

(In my case, as a ZooKeeper user via the Solr operator, I'd still have to figure out how to pass this env information from the SolrCloud CR definition to the ZookeeperCluster CR definition. But that's another discussion.)

We can add ENV to mention log level. But not sure if log level is mentioned via log4j-properties as well as ENV which one will take preference. Currently we are using log4j-properties and is hardcoded to INFO.

[anishakj]

By setting env in https://github.com/pravega/zookeeper-operator/blob/master/charts/zookeeper/values.yaml#L19 , logs are coming correctly for the pods according to the loge level set. Can we close this issue in that case?

[dalbani]

Yes, that's fine. Thank you.