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Posted to users@pulsar.apache.org by Apache Pulsar Slack <ap...@gmail.com> on 2019/09/30 09:11:05 UTC
Slack digest for #general - 2019-09-30
2019-09-29 20:00:22 UTC - Vladimir Shchur: Hi! I'm investigating if pulsar will be a good fit for implementing event sourcing. Looks like Pulsar SQL will be a good fit, but how can I use it from pulsar client? Can't find any guidance. Another thing that I'm looking for is events projection (resulting state) - looks like I can make it using pulsar function and store it in bookkeeper, but how will I query it using pulsar client?
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2019-09-30 02:12:04 UTC - jia zhai: please reference this link for SQL
<https://pulsar.apache.org/docs/en/sql-deployment-configurations/#query-pulsar-from-existing-presto-cluster>
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2019-09-30 02:12:46 UTC - jia zhai: And this link for state query:
<https://pulsar.apache.org/docs/en/functions-state/#query-state>
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2019-09-30 02:13:38 UTC - jia zhai: for records stored by pulsar functions, you could access it directly by topic consume
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2019-09-30 04:53:23 UTC - Vladimir Shchur: thank you, will take a look!
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2019-09-30 05:37:53 UTC - Vladimir Shchur: @jia zhai, it looks unclear for me how I can use saved state, say at any time my app wants to query current word count, how do I do it?
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2019-09-30 05:41:51 UTC - jia zhai: <https://pulsar.apache.org/docs/en/functions-state/#query-state>
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2019-09-30 05:42:10 UTC - jia zhai: <https://pulsar.apache.org/docs/en/functions-state/#java-api>
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2019-09-30 06:50:43 UTC - Shivji Kumar Jha: Hi, Can someone help me in understanding this prometheus metric: *pulsar_subscription_back_log*?
My consumers are working in shared mode and I expect this to reduce when I increase the number of consumer containers (producer throughput is constant). Not been falling for 48 hours..
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2019-09-30 06:53:37 UTC - Shivji Kumar Jha: pulsar_rate_in and pulsar_rate_out are always same, see below. This means my consumer is catching up with my producer.
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2019-09-30 08:09:06 UTC - Varun: @Varun has joined the channel
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2019-09-30 09:09:20 UTC - Shivji Kumar Jha: Another question on prometheus metrics. Why does prometheus show a huge number of topics when I have only one topic in the namespace?
1) GET /admin/v2/namespaces/<tenant>/<namespace>/topics returns 1 topic
2) prom query pulsar_topics_count{cluster=~"<cluster>", namespace=~"<namespace>"} returns count = 459
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