we have HDP cluster version 2.6.5   when we look on   name-node   logs we can see the following warning   2023-02-20 15:58:31,377 WARN server.Journal (Journal.java:journal(398)) - Sync of transaction 2023-02-20 16:00:39,037 WARN server.Journal (Journal.java:journal(398)) - Sync of transaction 2023-02-20 16:01:43,962 WARN server.Journal (Journal.java:journal(398)) - Sync of transaction range 193594954980-193594954980 took 1329ms 2023-02-20 16:02:47,129 WARN server.Journal (Journal.java:journal(398)) - Sync of transaction range 193595018764-193595018764 took 1321ms 2023-02-20 16:03:52,763 WARN server.Journal (Journal.java:journal(398)) - Sync of transaction range 193595106645-193595106646 took 1344ms 2023-02-20 16:04:56,276 WARN server.Journal (Journal.java:journal(398)) - Sync of transaction range 193595175233-193595175233 took 1678ms 2023-02-20 16:06:01,067 WARN server.Journal (Journal.java:journal(398)) - Sync of transaction range 193595252052-193595252052 took 1265ms 2023-02-20 16:07:06,447 WARN server.Journal (Journal.java:journal(398)) - Sync of transaction range 193595320796-193595320796 took 1273ms   in our HDP cluster , HDFS service include 2 name-node services and 3 journal-Nodes cluster include 736 data nodes machines , and HDFS service is the manager of all data-node   we want to understand what is the reason for the following warning ?   and how to avoid this messages by proactive solution server.Journal (Journal.java:journal(398)) - Sync of transaction range 193595018764-193595018764 took 1321ms ... View more

for now we have 15 Kafka machines in the cluster ,   all machines are are installed with RHEL 7.9 and the HW machine is DELL physical machine   Kafka version is 2.7 , and we have 3 zookeeper servers that serve the Kafka cluster   we decided to extend the Kafka cluster to ~100 machines , because Total Throughput In Megabytes increased dramatic   - note  according to Kafka confluent calculator we need around 100 Kafka machines   in that case I am wonder if our 3 zookeeper servers are enough to serve this huge cluster machines?   addition I want to say that our 3 zookeeper servers are already serve other application as HDFS , YARN , HIVE , spark etc. ... View more

we have HDP cluster version - 2.6.5 with Ambari platform   here is example from our Ambari lab cluster with 5 mode managers machines     regarding to YARN service - is it possible to add in Ambari the widget that can show CPU core consuming ?   if not what are the other ways to find the CORE consuming by YARN from cli ? other way that we found is from the `resource_manager:8088/cluster` as the following   so is it possible to find some API / CLI that can capture the VCores Used ?   ... View more

we have spark production cluster with YARN service ( based on HDP 2.6.5 version )   total node-managers services are - 745 ( actually 745 Linux machines )   and yarn   active resource-manager   and   standby resourcemanager   are installed on different masters machines   we found that the following parameters not defined in our YARN configuration ( yarn-site.xml ) ! yarn.scheduler.increment-allocation-vcores yarn.scheduler.increment-allocation-mb and above parameters not defined not in Ambari and not in YARN XML configuration files!   I want to know what the   meaning   of the parameter - yarn.scheduler.increment-allocation-vcores ?   and what is the affect if this parameters are not defined in our configuration?   from YARN best practice configuration we are understanding that both parameters are part of YARN configuration , but we not sure if we must to add them to YARN custom configuration   from documentation we found: Minimum and maximum allocation unit in YARN Two resources—memory and CPU, as of in Hadoop 2.5.1, have minimum and maximum allocation unit in YARN, as set by the configurations in yarn-site.xml. Basically, it means RM can only allocate memory to containers in increments of “yarn.scheduler.minimum-allocation-mb” and not exceed “yarn.scheduler.maximum-allocation-mb” It can only allocate CPU vcores to containers in increments of “yarn.scheduler.minimum-allocation-vcores” and not exceed “yarn.scheduler.maximum-allocation-vcores” If changes required, set above configurations in yarn-site.xml on RM nodes, and restart RM.   reference:   https://docs.trifacta.com/display/r076/Tune+Cluster+Performance   https://stackoverflow.com/questions/58522138/how-to-control-yarn-container-allocation-increment-properly   https://pratikbarjatya.github.io/learning/best-practices-for-yarn-resource-management/   https://stackoverflow.com/questions/58522138/how-to-control-yarn-container-allocation-increment-properly     ... View more

we have huge production Hadoop cluster, with HDP version 2.6.5 and ambari version 2.6.2.2 , and all machines are with OS RHEL 7.6 version   the cluster size is as the following :   Total workers machines - 425 ( each worker include data node and node manager service )   from time to time we get indication of lost one or two **node-manager** and this identified from Ambari as ( 424/425 when total node-manager  are 425 )   in order to fix it we just restart the **node-manager** and this action fix the problem and as results we get 425/425   after some googling , we found the following parameters that maybe should be tune better   yarn.client.nodemanager-connect.max-wait-ms ( its configured to 60000 ms and we think to increase it ) yarn.client.nodemanager-connect.retry-interval-ms ( its configured to 10 sec ms and we think to increase it ) yarn.nm.liveness-monitor.expiry-interval-ms ( this parameter not configured yet and we think to add it with value of 1500000 ms )   based on above details , I will appreciate to get comments or others ideas   background: NodeManager is LOST means that ResourceManager haven't received heartbeats from it for a duration of nm.liveness-monitor.expiry-interval-ms milliseconds (default is 10 minutes). ... View more

we have 3 Kafka brokers machines on on RHEL 7.9 Linux version ,   ( when each machine is physical strong `DELL HW` - memory = 512G and 96 CORE CPU )   Kafka cluster is in production mode     Kafka version is 2.7.x , and Kafka disks are in Jbod configuration each Kafka broker has 8 Jbod disks , as we can see from the following ( df -h details ) df -h /dev/sdc 1.7T 929G 748G 56% /kafka/kafka_logs2 /dev/sdd 1.7T 950G 727G 57% /kafka/kafka_logs3 /dev/sde 1.7T 999G 678G 60% /kafka/kafka_logs4 /dev/sdf 1.7T 971G 706G 58% /kafka/kafka_logs5 /dev/sdg 1.7T 1.7T 20K 100% /kafka/kafka-logs6 <----------------- /dev/sdh 1.7T 962G 714G 58% /kafka/kafka_logs7 /dev/sdi 1.7T 1.1T 621G 63% /kafka/kafka_logs8     as we can see from above disk - `/kafka/kafka_logs6` get `100%` used after short investigation we found that Kafka broker isn't tolerant when one disk is failed or disk reached to 100% , as results of this Kafka broker now is down here the Kafka `server.log`     [2022-11-29 15:43:59,723] ERROR Error while writing to checkpoint file /kafka/kafka-logs6 ............. java.io.IOException: No space left on device at java.io.FileOutputStream.writeBytes(Native Method) at java.io.FileOutputStream.write(FileOutputStream.java:326) at sun.nio.cs.StreamEncoder.writeBytes(StreamEncoder.java:221) at sun.nio.cs.StreamEncoder.implFlushBuffer(StreamEncoder.java:291) at sun.nio.cs.StreamEncoder.implFlush(StreamEncoder.java:295) at sun.nio.cs.StreamEncoder.flush(StreamEncoder.java:141) at java.io.OutputStreamWriter.flush(OutputStreamWriter.java:229) at java.io.BufferedWriter.flush(BufferedWriter.java:254) at kafka.server.checkpoints.CheckpointFile.liftedTree1$1(CheckpointFile.scala:108) at kafka.server.checkpoints.CheckpointFile.write(CheckpointFile.scala:92) at kafka.server.checkpoints.LeaderEpochCheckpointFile.write(LeaderEpochCheckpointFile.scala:70) at kafka.server.epoch.LeaderEpochFileCache.flush(LeaderEpochFileCache.scala:292) at kafka.server.epoch.LeaderEpochFileCache.$anonfun$truncateFromEnd$1(LeaderEpochFileCache.scala:238) at kafka.server.epoch.LeaderEpochFileCache.truncateFromEnd(LeaderEpochFileCache.scala:235) at kafka.log.Log.$anonfun$new$1(Log.scala:305) at kafka.log.Log.<init>(Log.scala:305) at kafka.log.Log$.apply(Log.scala:2549) at kafka.log.LogManager.loadLog(LogManager.scala:273) at kafka.log.LogManager.$anonfun$loadLogs$12(LogManager.scala:352) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:750) **from my perspective** when we have **8 disks** on each broker and one disks is failed ( like reached 100% ) , then we expect Kafka broker still be alive even one disk is failed so as results of above scenario we searched in Kafka `server.properties` the parameter that can help us to configure the Kafka broker to be tolerant when one disk is failed but we not found it , or maybe we not know what to set in order to define the kafka broker to be tolerant with one disk failure the full parameters are: more server.properties auto.create.topics.enable=false auto.leader.rebalance.enable=true background.threads=10 log.retention.bytes=-1 log.retention.hours=48 delete.topic.enable=true leader.imbalance.check.interval.seconds=300 leader.imbalance.per.broker.percentage=10 log.dir=/kafka/kafka-logs2,/kafka/kafka-logs3 ............... log.flush.interval.messages=9223372036854775807 log.flush.interval.ms=1000 log.flush.offset.checkpoint.interval.ms=60000 log.flush.scheduler.interval.ms=9223372036854775807 log.flush.start.offset.checkpoint.interval.ms=60000 compression.type=producer log.roll.jitter.hours=0 log.segment.bytes=1073741824 log.segment.delete.delay.ms=60000 message.max.bytes=1000012 min.insync.replicas=1 num.io.threads=10 num.network.threads=48 num.recovery.threads.per.data.dir=1 num.replica.fetchers=1 offset.metadata.max.bytes=4096 offsets.commit.required.acks=-1 offsets.commit.timeout.ms=5000 offsets.load.buffer.size=5242880 offsets.retention.check.interval.ms=600000 offsets.retention.minutes=10080 offsets.topic.compression.codec=0 offsets.topic.num.partitions=50 offsets.topic.replication.factor=3 offsets.topic.segment.bytes=104857600 queued.max.requests=1000 quota.consumer.default=9223372036854775807 quota.producer.default=9223372036854775807 replica.fetch.min.bytes=1 replica.fetch.wait.max.ms=500 replica.high.watermark.checkpoint.interval.ms=5000 replica.lag.time.max.ms=10000 replica.socket.receive.buffer.bytes=65536 replica.socket.timeout.ms=30000 request.timeout.ms=30000 socket.receive.buffer.bytes=102400 socket.request.max.bytes=104857600 socket.send.buffer.bytes=102400 transaction.max.timeout.ms=900000 transaction.state.log.load.buffer.size=5242880 transaction.state.log.min.isr=2 transaction.state.log.num.partitions=50 transaction.state.log.replication.factor=3 transaction.state.log.segment.bytes=104857600 transactional.id.expiration.ms=604800000 unclean.leader.election.enable=false zookeeper.connection.timeout.ms=600000 zookeeper.max.in.flight.requests=10 zookeeper.session.timeout.ms=600000 zookeeper.set.acl=false broker.id.generation.enable=true connections.max.idle.ms=600000 connections.max.reauth.ms=0 controlled.shutdown.enable=true controlled.shutdown.max.retries=3 controlled.shutdown.retry.backoff.ms=5000 controller.socket.timeout.ms=30000 default.replication.factor=3 delegation.token.expiry.time.ms=86400000 delegation.token.max.lifetime.ms=604800000 delete.records.purgatory.purge.interval.requests=1 fetch.purgatory.purge.interval.requests=1000 group.initial.rebalance.delay.ms=3000 group.max.session.timeout.ms=1800000 group.max.size=2147483647 group.min.session.timeout.ms=6000 log.cleaner.backoff.ms=15000 log.cleaner.dedupe.buffer.size=134217728 log.cleaner.delete.retention.ms=86400000 log.cleaner.enable=true log.cleaner.io.buffer.load.factor=0.9 log.cleaner.io.buffer.size=524288 log.cleaner.io.max.bytes.per.second=1.7976931348623157e308 log.cleaner.max.compaction.lag.ms=9223372036854775807 log.cleaner.min.cleanable.ratio=0.5 log.cleaner.min.compaction.lag.ms=0 log.cleaner.threads=1 log.cleanup.policy=delete log.index.interval.bytes=4096 log.index.size.max.bytes=10485760 log.message.timestamp.difference.max.ms=9223372036854775807 log.message.timestamp.type=CreateTime log.preallocate=false log.retention.check.interval.ms=300000 max.connections=2147483647 max.connections.per.ip=2147483647 max.incremental.fetch.session.cache.slots=1000 num.partitions=1 producer.purgatory.purge.interval.requests=1000 queued.max.request.bytes=-1 replica.fetch.backoff.ms=1000 replica.fetch.max.bytes=1048576 replica.fetch.response.max.bytes=10485760 reserved.broker.max.id=1500 transaction.abort.timed.out.transaction.cleanup.interval.ms=60000 transaction.remove.expired.transaction.cleanup.interval.ms=3600000 zookeeper.sync.time.ms=2000 broker.rack=/default-rack   I want to add my personal feeling: *just to gives here the absurder of the above scenario lets say we have on each Kafka broker 100 disks ( in Jbod ) is it make sense that Kafka broker will be shutdown just because one disk is failed ?* ... 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we have in our Hadoop cluster 3 Kafka machines, Kafka machines include the following services on kafka01: confluent kafka service confluent schema registry service zookeeper service on kafka02: confluent kafka service confluent schema registry service zookeeper service on kafka03: confluent kafka service confluent schema registry service zookeeper service on our Kafka cluster , we have different 34 topics one of the topic is topic name - `car.to.go` this topic include 3 replica in Kafka cluster what we found regarding to schema registry service , is that topic - `car.to.go` have different versions on kafka03 from other machines - `kafka01/02` so actually we get that versions are not in sync here is example: [root@kafka01 ~]# curl -X GET http://kafka01:8081/subjects/car.to.go-value/versions [1,2,3,4,5,6,7] [root@kafka01 ~]# curl -X GET http://kafka02:8081/subjects/car.to.go-value/versions [1,2,3,4,5,6,7] [root@kafka01 ~]# curl -X GET http://kafka03:8081/subjects/car.to.go-value/versions [1,2,3,4] from above info what could be the resewn that versions on kafka03 is diff from kafka01/02 regarding to topic `car.to.go` - what is the right way to fix this issue in way that we get on kafka03 the number versions as - `1,2,3,4,5,6,7` notes: all Kafka services and schema registry services and zookeeper services are up and running   links: https://github.com/confluentinc/schema-registry/blob/master/README.md https://docs.confluent.io/platform/current/schema-registry/develop/using.html#check-if-a-schema-is-registered-under-subject-kafka-key https://kafkawize.com/2019/03/17/commands-for-schemaregistry/   ... View more