# Auto\_expand\_replicas and shard allocation filtering **URL:** \ **Category:** Elasticsearch\ **Created:** [September 5, 2012, 1:48am UTC](https://discuss.elastic.co/t/auto-expand-replicas-and-shard-allocation-filtering/8928 "2012-09-05T01:48:33Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Mauri](https://avatars.discourse-cdn.com/v4/letter/m/c67d28/32.png) [@Mauri](https://discuss.elastic.co/u/Mauri)\ **Post date:** [September 5, 2012, 1:48am UTC](https://discuss.elastic.co/t/auto-expand-replicas-and-shard-allocation-filtering/8928/1 "2012-09-05T01:48:33Z")
Hello, If I configure the nodes in my cluster to have a node attribute 'node.zone' with values "zone1", "zone1", etc and then configure an index as follows: curl -XPUT localhost:9200/test/\_settings -d '{ "index.routing.allocation.include.zone" : "zone1", "index.auto\_expand\_replicas" : "0-all" }' Will elasticsearch auto expand the replica shards for index 'test' only within zone1 or will the auto\_expand\_replicas option ignore the shard allocation directives and auto replicate across the entire cluster? Regards Mauri -- ---
**Author:** ![Mauri](https://avatars.discourse-cdn.com/v4/letter/m/c67d28/32.png) [@Mauri](https://discuss.elastic.co/u/Mauri)\ **Post date:** [September 5, 2012, 2:58pm UTC](https://discuss.elastic.co/t/auto-expand-replicas-and-shard-allocation-filtering/8928/2 "2012-09-05T14:58:11Z")
Hello, Decided to do a test to investigate this. With an index configured with auto\_expand\_replicas="0-all" the cluster will try to allocate one primary and ({number nodes} - 1) replicas for each shard, ie a copy of each shard on each node. However, with "index.routing.allocation.include.zone"="zone1" the cluster is blocked from allocating a shard (either primary or replica) to any nodes that are not configured with a zone attribute set to "zone1", ie "node.zone=zone1" in the elasticsearch.yaml config file. So if a cluster has 3 nodes in "zone1" and 3 nodes in "zone2" it will allocate 3 shards (primary + 2 x replicas) to the "zone1" nodes and mark an additional 3 replicas as unassigned. I observed this using the elasticsearch head utility. So the allocation behaviour is as desired, ie auto expand replicas to all nodes with a specific zone attribute. I do not know if the unassigned replicas will cause problems for the cluster. Can anyone add to this? Below is the HTTP request I used to create the index Request --------------------------------------------- POST /test8 HTTP/1.0 Host: localhost:9200 Content-Type: application/json Content-Length: 178 { "settings" : { "index" : { "number\_of\_shards" : 1, "auto\_expand\_replicas" : "0-all", "routing" : {"allocation" : {"include" : {"zone" : "zone1"}}} } }} Response -------------------------------------------- HTTP/1.0 200 OK Content-Type: application/json; charset=UTF-8 Content-Length: 31 {"ok":true,"acknowledged":true} End ---------------------------------------------- Regards Mauri -- ---
**Author:** ![Itamar\_Syn\_Hershko](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/itamar_syn_hershko/32/725_2.png) [@Itamar\_Syn\_Hershko](https://discuss.elastic.co/u/Itamar_Syn_Hershko)\ **Post date:** [April 7, 2013, 6:10pm UTC](https://discuss.elastic.co/t/auto-expand-replicas-and-shard-allocation-filtering/8928/3 "2013-04-07T18:10:09Z")
We are experiencing this as well. The Unassigned shards in this case (when auto-expand-replica is set to some value and the index has include/exclude stuff set) will make your cluster status be in RED state, which is bad. I opened a ticket for this here: > > > With an index configured with auto\_expand\_replicas="0-all" the cluster will try …to allocate one primary and ({number nodes} - 1) replicas for each shard, ie a copy of each shard on each node. > > However, with "index.routing.allocation.include.zone"="zone1" the cluster is blocked from allocating a shard (either primary or replica) to any nodes that are not configured with a zone attribute set to "zone1", ie "node.zone=zone1" in the elasticsearch.yaml config file. So if a cluster has 3 nodes in "zone1" and 3 nodes in "zone2" it will allocate 3 shards (primary + 2 x replicas) to the "zone1" nodes and mark an additional 3 replicas as unassigned. I observed this using the elasticsearch head utility. > > So the allocation behaviour is as desired, ie auto expand replicas to all nodes with a specific zone attribute, but the unassigned shards will make the cluster be in red state > > See https://groups.google.com/forum/#!msg/elasticsearch/95hC-wGu7GE/BPPSWsfj8UkJ On Wednesday, September 5, 2012 5:58:11 PM UTC+3, Mauri wrote: > Hello, Decided to do a test to investigate this. > > With an index configured with auto\_expand\_replicas="0-all" the cluster > will try to allocate one primary and ({number nodes} - 1) replicas for each > shard, ie a copy of each shard on each node. > > However, with "index.routing.allocation.include.zone"="zone1" the cluster > is blocked from allocating a shard (either primary or replica) to any nodes > that are not configured with a zone attribute set to "zone1", ie > "node.zone=zone1" in the elasticsearch.yaml config file. So if a cluster > has 3 nodes in "zone1" and 3 nodes in "zone2" it will allocate 3 shards > (primary + 2 x replicas) to the "zone1" nodes and mark an additional 3 > replicas as unassigned. I observed this using the elasticsearch head > utility. > > So the allocation behaviour is as desired, ie auto expand replicas to all > nodes with a specific zone attribute. > I do not know if the unassigned replicas will cause problems for the > cluster. > Can anyone add to this? > > Below is the HTTP request I used to create the index > > Request --------------------------------------------- > POST /test8 HTTP/1.0 > Host: localhost:9200 > Content-Type: application/json > Content-Length: 178 > > { "settings" : { "index" : { "number\_of\_shards" : 1, > "auto\_expand\_replicas" : "0-all", "routing" : {"allocation" : > {"include" : {"zone" : "zone1"}}} } }} > Response -------------------------------------------- > HTTP/1.0 200 OK > Content-Type: application/json; charset=UTF-8 > Content-Length: 31 > > {"ok":true,"acknowledged":true} > End ---------------------------------------------- > > Regards > Mauri -- 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). For more options, visit [https://groups.google.com/groups/opt\_out](https://groups.google.com/groups/opt_out). ---
**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, 2:42am UTC](https://discuss.elastic.co/t/auto-expand-replicas-and-shard-allocation-filtering/8928/4 "2017-07-06T02:42:21Z")