# Can a replica be updated with the deltas only? **URL:** \ **Category:** Elasticsearch\ **Created:** [March 10, 2014, 3:41pm UTC](https://discuss.elastic.co/t/can-a-replica-be-updated-with-the-deltas-only/16271 "2014-03-10T15:41:26Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Yves\_Dorfsman](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/yves_dorfsman/32/1106_2.png) [@Yves\_Dorfsman](https://discuss.elastic.co/u/Yves_Dorfsman)\ **Post date:** [March 10, 2014, 3:41pm UTC](https://discuss.elastic.co/t/can-a-replica-be-updated-with-the-deltas-only/16271/1 "2014-03-10T15:41:26Z")
When I shutdown a node that holds a replica and updates are happening to the rest of the cluster, then re-start this node, it seems that the entire replica is being copied again to that node. Is there a way to make ES just update that node with the updates that happened while it was down? Thanks. -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/2d6138a0-5b4d-4ab4-9ef8-2f94beaef241%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/2d6138a0-5b4d-4ab4-9ef8-2f94beaef241%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![Binh\_Ly\_2](https://avatars.discourse-cdn.com/v4/letter/b/d07c76/32.png) [@Binh\_Ly\_2](https://discuss.elastic.co/u/Binh_Ly_2)\ **Post date:** [March 10, 2014, 4:11pm UTC](https://discuss.elastic.co/t/can-a-replica-be-updated-with-the-deltas-only/16271/2 "2014-03-10T16:11:11Z")
I don't believe this is possible. ES does sync replication by default and then when a replica is down while updates/inserts are coming in, that replica is simply invalidated and then fully recovered later once it comes back up. -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/a9734310-58d9-4f0f-bc98-f7ef9bf7bd29%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/a9734310-58d9-4f0f-bc98-f7ef9bf7bd29%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![Clinton\_Gormley](https://avatars.discourse-cdn.com/v4/letter/c/50afbb/32.png) [@Clinton\_Gormley](https://discuss.elastic.co/u/Clinton_Gormley)\ **Post date:** [March 10, 2014, 4:49pm UTC](https://discuss.elastic.co/t/can-a-replica-be-updated-with-the-deltas-only/16271/3 "2014-03-10T16:49:12Z")
If a replica recovers from the primary, then the node hosting it is shut down shortly thereafter, when it comes back up it will only copy the segments that have changed in the interim period. However, merges happen independently on the primary and the replica. When a replica has been running for a long time, its segments will have diverged from those of the primary, and so more segments need to be copied across. In the future we hope to improve this process. On 10 March 2014 17:11, Binh Ly [binhly\_es@yahoo.com](mailto:binhly_es@yahoo.com) wrote: > I don't believe this is possible. ES does sync replication by default and > then when a replica is down while updates/inserts are coming in, that > replica is simply invalidated and then fully recovered later once it comes > back up. > > -- > You received this message because you are subscribed to the Google Groups > "elasticsearch" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). > To view this discussion on the web visit > [https://groups.google.com/d/msgid/elasticsearch/a9734310-58d9-4f0f-bc98-f7ef9bf7bd29%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/a9734310-58d9-4f0f-bc98-f7ef9bf7bd29%40googlegroups.com)[https://groups.google.com/d/msgid/elasticsearch/a9734310-58d9-4f0f-bc98-f7ef9bf7bd29%40googlegroups.com?utm\_medium=email&utm\_source=footer](https://groups.google.com/d/msgid/elasticsearch/a9734310-58d9-4f0f-bc98-f7ef9bf7bd29%40googlegroups.com?utm_medium=email&utm_source=footer) > . > > For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/CAPt3XKR1By1eO61z7Knju4\_QAQdUEjT0t5\_4LAh%3D%2BXNkAUVkmw%40mail.gmail.com](https://groups.google.com/d/msgid/elasticsearch/CAPt3XKR1By1eO61z7Knju4_QAQdUEjT0t5_4LAh%3D%2BXNkAUVkmw%40mail.gmail.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![Binh\_Ly\_2](https://avatars.discourse-cdn.com/v4/letter/b/d07c76/32.png) [@Binh\_Ly\_2](https://discuss.elastic.co/u/Binh_Ly_2)\ **Post date:** [March 10, 2014, 5:49pm UTC](https://discuss.elastic.co/t/can-a-replica-be-updated-with-the-deltas-only/16271/4 "2014-03-10T17:49:05Z")
I stand corrected. Clint is right. ES will try to apply only diffs as much as possible at the segment level. But if your underlying segments have diverged significantly since the replica node went down, it is likely that you'll end up with copying a lot more than the diffs (document-wise). Otherwise, it'll just copy segments that have changed. 🙂 -- You received this message because you are subscribed to the Google Groups "elasticsearch" group. To unsubscribe from this group and stop receiving emails from it, send an email to [elasticsearch+unsubscribe@googlegroups.com](mailto:elasticsearch+unsubscribe@googlegroups.com). To view this discussion on the web visit [https://groups.google.com/d/msgid/elasticsearch/3557d64f-b326-4776-ba8e-42e923d2b30a%40googlegroups.com](https://groups.google.com/d/msgid/elasticsearch/3557d64f-b326-4776-ba8e-42e923d2b30a%40googlegroups.com). For more options, visit [https://groups.google.com/d/optout](https://groups.google.com/d/optout). ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [July 6, 2017, 1:44am UTC](https://discuss.elastic.co/t/can-a-replica-be-updated-with-the-deltas-only/16271/5 "2017-07-06T01:44:29Z")
Closed on July 6, 2017, 1:44am UTC