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Questions tagged [apache-zookeeper]

Apache ZooKeeper is a distributed service that provides configuration information storage, naming, synchronization, coordination, and group services.

ZooKeeper is a centralized service for maintaining configuration information, naming, providing distributed synchronization, and providing group services. It was inspired by Chubby, Google's distributed lock system.

All of these kinds of services are used in some form or another by distributed applications. Each time they are implemented there is a lot of work that goes into fixing the bugs and race conditions that are inevitable. Because of the difficulty of implementing these kinds of services, applications initially usually skimp on them, which makes them brittle in the presence of change and difficult to manage. Even when done correctly, different implementations of these services lead to management complexity when the applications are deployed.

ZooKeeper is used by a variety of other software projects to maintain configuration information including Apache Storm, Apache Flink, Solr Cloud, Apache Kafka and Apache Hadoop.

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Reloading SolrCloud configuration (stored on Zookeeper) - schema.xml

I have setup a SolrCloud replication using standalone zookeeper. But now I wish to make some changes to my Schema.xml and reload the core. The problem is that when I run a single server Solr (no solrcloud) the new schema is loaded, but I do not know…
Global Warrior
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How to recover Zookeeper from java.io.EOFException after a server crash?

How to recover from the following error that started happening after a server crash? Zookeeper won’t start and the following message is showing repeatedly on the log. 2017-05-27 01:02:08,072 [myid:] - INFO [main:Environment@100] - Server…
user3395041
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KeeperErrorCode = NoNode for /admin/preferred_replica_election

when i starting kafka,zookeeper happens error. INFO Got user-level KeeperException when processing sessionid:0x156028651c00001 type:delete cxid:0x1b zxid:0x59 txntype:-1 reqpath:n/a Error Path:/admin/preferred_replica_election Error:KeeperErrorCode…
Lehman He
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How to manage/balance semi persistent jobs over service instances

I see a common pattern for services that we try to develop and I wonder if there are tools / libraries out there that would help here. While the default jobs as discussed in microservice literature is from the REQUEST -> RESPONSE nature, our jobs…
Joost Pastoor
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Can Mesos 'master' and 'slave' nodes be deployed on the same machines?

Can Apache Mesos 'master' nodes be co-located on the same machine as Mesos 'slave' nodes? Similarly (for high-availability (HA) deploys), can the Apache Zookeeper nodes used in Mesos 'master' election be deployed on the same machines as Mesos…
Ethan
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kafka NoClassDefFoundError kafka/Kafka

Regarding Apache-Kafka messaging queue. I have downloaded Apache Kafka from the Kafka download page. I've extracted it to /opt/apache/installed/kafka-0.7.0-incubating-src. The quickstart page says you need to start zookeeper and then start Kafka by…
summerbulb
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How do you backup Zookeeper?

I have read that copying the data directory will work. But, that is a combination of logs and snapshots. How do folks backup a zookeeper infrastructure ? Export ? Dump ? Custom script ? What are the best practices ?
Krishna Sankar
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Zookeeper admin server Port

Installed zookeeper 3.5.6 bin on windows. Getting error: Unable to start AdminServer, exiting abnormally org.apache.zookeeper.server.admin.AdminServer$AdminServerException: Problem starting AdminServer on address 0.0.0.0, port 8080 and command URL…
Sam-T
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How to restart kafka server properly?

Every time I stop the kafka server and start it again it doesn't start properly and I have to restart my whole machine and start the kafka server. Does anybody know how I can restart kafka server without having to restart my machine? Actually I…
Zeinab Akhavan
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What happens if Zookeeper fails completely?

we have setup a Kafka/Zookeeper Cluster consisting of 3 Brokers. We have one producer, sending messages to one specific Kafka topic and a few consumer groups reading from said topic. Those consumers perform a leader election via Zookeeper for…
tehK
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What's the difference between zookeeper vs spring cloud config server?

What's the difference between zookeeper vs spring cloud config server? They both store configurations in server and make them available to clients. When should one be used over the other?
user321532
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ZooKeeper internal behavior on split brain scenario

I am trying to understand the internal workings of Apache ZooKeeper in split brain situations. Suppose there is a cluster of 5 servers: A, B, C, D and E, where A is the leader. Now suppose the subcluster {A, B} gets separated from the the subcluster…
Gabriel
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embedded zookeeper for unit/integration test

Is there an embedded zookeeper so that we could use it in unit testing? It can be shipped with the test and run out of the box. Maybe we could mock some service and register to the embedded zookeeper
blue123
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How do I initialize the whitelist for Apache-Zookeeper?

I'm new to Apache Kafka. I've installed it into a Ubuntu Linux VM (18.04). I've started up Zookeeper from the Kafka directory with the default configuration. The Zookeeper looks like it started successfully. From another Terminal window I am…
JohnB
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Kafka Multi Node setup "Unreasonable length" in Zookeeper logs

I have setup a multi node setup for kafka, everything seems to work well and show no error logs unless i try to push message to one producer. I get a message: Bootstrap broker host2:2181 disconnected (org.apache.kafka.clients.NetworkClient) and on…
vaibhav
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