# Akka Persistence Cassandra - High RU/s on tag\_views table

**URL:** <https://discuss.akka.io/t/akka-persistence-cassandra-high-ru-s-on-tag-views-table/7416>\
**Category:** Persistence / Event Sourcing\
**Created:** [November 3, 2020, 9:39am UTC](https://discuss.akka.io/t/akka-persistence-cassandra-high-ru-s-on-tag-views-table/7416 "2020-11-03T09:39:27Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![agapic](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.akka.io/agapic/32/2003_2.png) [@agapic](https://discuss.akka.io/u/agapic)\
**Post date:** [November 3, 2020, 9:39am UTC](https://discuss.akka.io/t/akka-persistence-cassandra-high-ru-s-on-tag-views-table/7416/1 "2020-11-03T09:39:27Z")

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I’m currently using Akka Persistence w/ the Datastax Cassandra plugin against CosmosDB. I also leverage Akka Persistence Query to create a projection from a Cassandra Read Journal. (see below)

The thing is, running our projections with _no_ new events coming in, I’m seeing ~186 RU/s (approximately, requests/second) against our DB on the akka.tag\_views table when the projection is running. I’m running **12** instances of a projection. My tags are “aggregate-slice-{1,12}” naturally. This load seems incredibly high and it feels like the DB is extremely busy. How do I make things more reasonable?

**Edit:** I’ve narrowed the high load down to query.refresh-interval and backtrack.interval. Why is the default backtrack interval 1 second? That seems pretty frequent in conjunction with polling queries every 2 seconds.

```
cassandra {
  events-by-tag {
    bucket-size = "Day"
    eventual-consistency-delay = 200ms # i've tinkered with this from 200ms to 5s
    flush-interval = 50ms
    pubsub-notification = on
    first-time-bucket = "20201102T00:00"
    gc-grace-seconds = 0
    back-track {
       interval = 1s
       long-interval = 120s
    }
  }

  query {
    refresh-interval = 2s
  }

```

```auto
    SourceProvider<Offset, EventEnvelope<Message>> sourceProvider = EventSourcedProvider
        .eventsByTag(
            system,
            CassandraReadJournal.Identifier(),
            tag
        );

    return CassandraProjection.atLeastOnce(
        ProjectionId.of(PROJECTION_NAME, tag),
        sourceProvider,
        new ProjectionHandler(system, tag, producer)
    );

```

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<div class="post-metadata">

**Author:** ![Simiil](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.akka.io/simiil/32/1194_2.png) [@Simiil](https://discuss.akka.io/u/Simiil)\
**Post date:** [February 16, 2022, 3:54pm UTC](https://discuss.akka.io/t/akka-persistence-cassandra-high-ru-s-on-tag-views-table/7416/2 "2022-02-16T15:54:09Z")

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Did you ever find a solution for this? I’m unfortunately facing the same issue…