Slack digest for #general - 2018-06-07

[Apache Pulsar Slack <ap...@gmail.com>]

2018-06-06 09:34:32 UTC - Idan: hi guys, iam trying to run pulsar standalone. and it wont come up. perhaps you have an idea?
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2018-06-06 09:35:07 UTC - Idan: @Idan uploaded a file: <https://apache-pulsar.slack.com/files/UALJD8929/FB2LTB5NZ/-.java|Untitled>
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2018-06-06 09:35:41 UTC - Ali Ahmed: try deleting the data directory it seems previous data is present
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2018-06-06 09:36:36 UTC - Idan: just did. same thing. adding snippet
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2018-06-06 09:36:44 UTC - Idan: @Idan uploaded a file: <https://apache-pulsar.slack.com/files/UALJD8929/FB2GSG64S/-.java|Untitled>
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2018-06-06 09:38:11 UTC - Idan: ok it worked. thanks
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2018-06-06 09:38:22 UTC - Idan: do we know why it can happen? need to pay attention for it in prod
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2018-06-06 09:38:29 UTC - Ali Ahmed: it looks like a zombie process is running
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2018-06-06 09:38:36 UTC - Ali Ahmed: ```
12:36:06.644 [main] ERROR org.apache.pulsar.zookeeper.LocalBookkeeperEnsemble - Exception while instantiating ZooKeeper
java.net.BindException: Address already in use
	at sun.nio.ch.Net.bind0(Native Method) ~[?:1.8.0_144]
	at sun.nio.ch.Net.bind(Net.java:433) ~[?:1.8.0_144]
	at sun.nio.ch.Net.bind(Net.java:425) ~[?:1.8.0_144]
	at sun.nio.ch.ServerSocketChannelImpl.bind(ServerSocketChannelImpl.java:223) ~[?:1.8.0_144]
	at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:74) ~[?:1.8.0_144]
	at sun.nio.ch.ServerSocketAdaptor.bind(ServerSocketAdaptor.java:67) ~[?:1.8.0_144]
	at org.apache.zookeeper.server.NIOServerCnxnFactory.configure(NIOServerCnxnFactory.java:90) ~[org.apache.pulsar-pulsar-broker-2.0.0-rc1-incubating.jar:2.0.0-rc1-incubating]
	at org.apache.pulsar.zookeeper.LocalBookkeeperEnsemble.runZookeeper(LocalBookkeeperEnsemble.java:123) [org.apache.pulsar-pulsar-zookeeper-utils-2.0.0-rc1-incubating.jar:2.0.0-rc1-incubating]
	at org.apache.pulsar.zookeeper.LocalBookkeeperEnsemble.startStandalone(LocalBookkeeperEnsemble.java:241) [org.apache.pulsar-pulsar-zookeeper-utils-2.0.0-rc1-incubating.jar:2.0.0-rc1-incubating]
	at org.apache.pulsar.PulsarStandaloneStarter.start(PulsarStandaloneStarter.java:171) [org.apache.pulsar-pulsar-broker-2.0.0-rc1-incubating.jar:2.0.0-rc1-incubating]
	at org.apache.pulsar.PulsarStandaloneStarter.main(PulsarStandaloneStarter.java:266) [org.apache.pulsar-pulsar-broker-2.0.0-rc1-incubating.jar:2.0.0-rc1-incubating]
12:36:06.659 [main] INFO  org.apache.pulsar.zookeeper.LocalBookkeeperEnsemble - Server UP
```
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2018-06-06 10:01:41 UTC - Idan: Got it. Thanks
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2018-06-06 22:56:58 UTC - John: @John has joined the channel
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2018-06-06 23:07:38 UTC - John: Hi! I'm a Pulsar newbie. I was looking at the docs and see that ```Subscriptions are local to a cluster``` and that when transfer a subcription you have to make a new subscription
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2018-06-06 23:09:34 UTC - Sijie Guo: you mean transfer subscription from one data center to the other data center?
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2018-06-06 23:09:35 UTC - John: Is there a standard way to be able to catch this subscription up to minimize duplicates? Both for cumulative ack and for individual ack?
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2018-06-06 23:09:47 UTC - John: Yeah that would be ideal @Sijie Guo
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2018-06-06 23:13:12 UTC - Sijie Guo: @John yeah currently the subscription is local to a data center. when you transfer the subscription from one data center to the other data center, the subscription is new even it is same subscription name. the only way (for now) to keep subscription “in-sync” between data centers is you can rewind back to x amount of time during transfer, but the downside of that is you might see duplications in that x amount of time window.

Although there is an ongoing discussion to handle transparent subscription transfer and passive cluster failover, hopefully we will have a PIP out for that and planned in subsequent releases soon.

Hope this answer your question.
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2018-06-06 23:13:43 UTC - John: Awesome thanks!
ok_hand : Sijie Guo
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