docs(runbooks): add CollectorSourceDiscardedLogs runbook

[vparfonov]

Document diagnosis and mitigation steps for when log collector sources discard lines exceeding maxMessageSize.

[openshift-ci]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: vparfonov
Once this PR has been reviewed and has the lgtm label, please assign jcantrill for approval. For more information see the Code Review Process.

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

• alerts/cluster-logging-operator/OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[vparfonov]

/hold

[vparfonov]

/assign @jcantrill

[openshift-ci]

@vparfonov: all tests passed!

Full PR test history. Your PR dashboard.

Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository. I understand the commands that are listed here.