[KAFKA-9376] Plugin class loader not found using MM2

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.4.0
• Fix Version/s: 2.5.0
• Component/s: mirrormaker
• Assignee: Unassigned
• Reporter: Sinóros-Szabó Péter
• Created: 07/Jan/20 15:47
• Updated: 12/Feb/24 22:32
• Resolved: 12/Feb/24 22:32

Description

I am using MM2 (release 2.4.0 with scala 2.12) I geta bunch of classloader errors. MM2 seems to be working, but I do not know if all of it components are working as expected as this is the first time I use MM2.

I run MM2 with the following command:

./bin/connect-mirror-maker.sh config/connect-mirror-maker.properties

Errors are:

[2020-01-07 15:06:17,892] ERROR Plugin class loader for connector: 'org.apache.kafka.connect.mirror.MirrorHeartbeatConnector' was not found. Returning: org.apache.kafka.connect.runtime.isolation.DelegatingClassLoader@6ebf0f36 (org.apache.kafka.connect.runtime.isolation.DelegatingClassLoader:165)
[2020-01-07 15:06:17,889] ERROR Plugin class loader for connector: 'org.apache.kafka.connect.mirror.MirrorHeartbeatConnector' was not found. Returning: org.apache.kafka.connect.runtime.isolation.DelegatingClassLoader@6ebf0f36 (org.apache.kafka.connect.runtime.isolation.DelegatingClassLoader:165)
[2020-01-07 15:06:17,904] INFO ConnectorConfig values:
 config.action.reload = restart
 connector.class = org.apache.kafka.connect.mirror.MirrorHeartbeatConnector
 errors.log.enable = false
 errors.log.include.messages = false
 errors.retry.delay.max.ms = 60000
 errors.retry.timeout = 0
 errors.tolerance = none
 header.converter = null
 key.converter = null
 name = MirrorHeartbeatConnector
 tasks.max = 1
 transforms = []
 value.converter = null
 (org.apache.kafka.connect.runtime.ConnectorConfig:347)
[2020-01-07 15:06:17,904] INFO EnrichedConnectorConfig values:
 config.action.reload = restart
 connector.class = org.apache.kafka.connect.mirror.MirrorHeartbeatConnector
 errors.log.enable = false
 errors.log.include.messages = false
 errors.retry.delay.max.ms = 60000
 errors.retry.timeout = 0
 errors.tolerance = none
 header.converter = null
 key.converter = null
 name = MirrorHeartbeatConnector
 tasks.max = 1
 transforms = []
 value.converter = null
 (org.apache.kafka.connect.runtime.ConnectorConfig$EnrichedConnectorConfig:347)
[2020-01-07 15:06:17,905] INFO TaskConfig values:
 task.class = class org.apache.kafka.connect.mirror.MirrorHeartbeatTask
 (org.apache.kafka.connect.runtime.TaskConfig:347)
[2020-01-07 15:06:17,905] INFO Instantiated task MirrorHeartbeatConnector-0 with version 1 of type org.apache.kafka.connect.mirror.MirrorHeartbeatTask (org.apache.kafka.connect.runtime.Worker:434)

After a while, these errors are not logged any more.

Config is:

clusters = eucmain, euwbackup
eucmain.bootstrap.servers = kafka1:9092,kafka2:9092
euwbackup.bootstrap.servers = 172.30.197.203:9092,172.30.213.104:9092
eucmain->euwbackup.enabled = true
eucmain->euwbackup.topics = .*
eucmain->euwbackup.topics.blacklist = ^(kafka|kmf|__|pricing).*
eucmain->euwbackup.rename.topics = false
rename.topics = false
eucmain->euwbackup.sync.topic.acls.enabled = false
sync.topic.acls.enabled = false

Using OpenJDK 8 or 11, I get the same error.

 

Issue Links

• is related to: KAFKA-9827 MM2 doesnt replicate data
• relates to: KAFKA-8340 ServiceLoader fails when used from isolated plugin path directory