Slack digest for #general - 2020-10-03

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

2020-10-02 09:53:38 UTC - Enrico: hi in my test, if i send message with async into non-persistent topic I lost 40% messages, because I send 50k messages and consumer consume 30k, if i use sync or i change topic with a persistent topic, i don't lost any message i send 50k and i receive 50k, how i can fix this problem?
----
2020-10-02 09:54:31 UTC - Enrico: Ah if i set a sleep 1ns for every message i send from producer i don't lost message. i have problem only if i send messages with async and non-persistent topic without sleep
----
2020-10-02 10:16:27 UTC - Toktok Rambo: hello all I’m using Pulsar with the Go client (<http://github.com/apache/pulsar-client-go/pulsar|github.com/apache/pulsar-client-go/pulsar>); even though I have specified a topic, it’s still receiving messages from other topics :confused:
any idea when would this happen? I’ve confirmed the producer of the respective message has an appropriate Topic as well
----
2020-10-02 11:02:56 UTC - Shivji Kumar Jha: @Toktok Rambo Hey, can you share the sample sample code maybe that does that?
----
2020-10-02 12:25:49 UTC - Alan Hoffmeister: That's great! Thx a lot!
----
2020-10-02 13:28:23 UTC - Łukasz Śnieżewski: @Łukasz Śnieżewski has joined the channel
----
2020-10-02 16:45:08 UTC - Jim M.: any tuning guides. Currently for a cluster of 9 bk, brokers, 5 zk. With any number of partitions. Im stuck at 100 msg per second
----
2020-10-02 16:48:49 UTC - Claude: @Claude has joined the channel
----
2020-10-02 17:02:33 UTC - Addison Higham: from your producer? that seems quite low. What client and client config are you using?
----
2020-10-02 17:03:46 UTC - Jim M.: Yup. Was using the pref test tool in the broker
----
2020-10-02 17:03:56 UTC - Jim M.: And java client normally with default configs
----
2020-10-02 17:09:28 UTC - Addison Higham: can you share details of your cluster like JVM sizes and the commands you are using for pulsar-perf?
----
2020-10-02 17:11:32 UTC - Jim M.: Pref producer topic name
----
2020-10-02 17:14:13 UTC - Jim M.: Grabbing stats
----
2020-10-02 17:16:54 UTC - Jim M.: Xmx on broker is 4096
----
2020-10-02 17:20:16 UTC - Jim M.: 1024 for bk
----
2020-10-02 17:20:20 UTC - Jim M.: 512 for zk
----
2020-10-02 17:20:52 UTC - Jim M.: 1 cpu bk, 2 cpu for broker, .5 zk
----
2020-10-02 17:29:20 UTC - Addison Higham: what disks are you using for bookies? also, are you using multiple partitions?
----
2020-10-02 17:29:43 UTC - Addison Higham: because a single partition can only use a single broker and is limited by bookies
----
2020-10-02 17:29:48 UTC - Jim M.: Rook ceph but underlying disk us local
----
2020-10-02 17:30:24 UTC - Jim M.: So more brokers then? With more partitions?
----
2020-10-02 17:31:30 UTC - Addison Higham: just more partitions should work
----
2020-10-02 17:32:35 UTC - Jim M.: Did that. Went from 27, 36, 56. Same result
----
2020-10-02 17:36:41 UTC - Addison Higham: how large are your messages? assuming 1kb messages, that performance is very low. Have you looked and seen in some how you placed producer rate limits? Or perhaps your pulsar-perf client process is being constrained somehow?
----
2020-10-02 17:37:08 UTC - Jim M.: 8 kb decompressed
----
2020-10-02 17:37:21 UTC - Jim M.: No rate limits im aware of.
----
2020-10-02 17:37:30 UTC - Jim M.: We are doing key shared strategy
----
2020-10-02 17:37:56 UTC - Jim M.: Network internally is 10 gb fiber
----
2020-10-02 18:05:28 UTC - Priyath Gregory: @Addison Higham same question posted here :)
----
2020-10-02 18:46:56 UTC - Addison Higham: key shared on consumers I assume? pulsar-perf doesn't really have key shared support?
----
2020-10-02 18:58:14 UTC - Addison Higham: sorry for delay, I keep going back and forth, I remember thinking about this extensively when I worked on this code last and concluded it was safe but did involve some small details, but now I can't remember the details and am questioning again :stuck_out_tongue:

One thing to note though is the call to checkpoint is blocking and only happens after messages have been enqueued, but it does seem like queue would need to be drained before we checkpoint. I actually didn't implement all this code initially, but just refactored. Let me look at this more see if I can get an answer. But in the meantime, it might make sense to open an issue
----
2020-10-02 18:58:52 UTC - Addison Higham: @Priyath Gregory ^^
----
2020-10-02 20:03:31 UTC - Addison Higham: @Jim M. it is hard to say where it is going wrong without knowing more, if you are running prometheus/grafana, the default dashboard might be illuminating. Also, I am happy to jump on a 30 min call and see if we can diagnose it
----
2020-10-02 21:18:16 UTC - Andy Papia: Just need a sanity check... I'm publishing messages to a topic from the python client and trying to stream them out with the pulsar-client binary (also tried the java client).  If I connect to the topic as a consumer while the publisher is publishing, I get events.  But if I wait until after the producer has disconnected, I don't get any events despite specifying `Earliest` on my subscription.  At first I though this was because I had persistence disabled on minikube (though we thought it should still be in broker memory), but even with persistence enabled, this is the behavior I see.
----
2020-10-02 21:18:21 UTC - Andy Papia: Am I missing something?
----
2020-10-02 21:28:03 UTC - Addison Higham: If you don't have any existing subscriptions or a persistence policy, pulsar discards messages.

You can either create a subscription then publish and later consume or set a persistence policy for the namespace
----
2020-10-03 00:22:54 UTC - Andy Papia: excellent thanks!
----
2020-10-03 02:26:12 UTC - Priyath Gregory: @Addison Higham @David Kjerrumgaard Created an issue
for this. I don't seem to have permission to assign it to a user though. <https://issues.apache.org/jira/browse/PULSAR-7>
----
2020-10-03 02:26:54 UTC - Addison Higham: We use github for issues, not jira
+1 : Priyath Gregory
----
2020-10-03 02:32:27 UTC - Priyath Gregory: Apologies! my bad. <https://github.com/apache/pulsar/issues/8192>
----