# Reindexing Elasticsearch index with parent and child relationship **URL:** \ **Category:** Elasticsearch\ **Created:** [September 21, 2017, 12:47pm UTC](https://discuss.elastic.co/t/reindexing-elasticsearch-index-with-parent-and-child-relationship/101331 "2017-09-21T12:47:11Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![benjes](https://avatars.discourse-cdn.com/v4/letter/b/c5a1d2/32.png) [@benjes](https://discuss.elastic.co/u/benjes)\ **Post date:** [September 21, 2017, 12:47pm UTC](https://discuss.elastic.co/t/reindexing-elasticsearch-index-with-parent-and-child-relationship/101331/1 "2017-09-21T12:47:11Z")
Hi we currently have a 'message' that can have a link to a 'parent' message. E.g. a reply would have the original message as the parent\_id. ``` PUT { "mappings": { "message": { "properties": { "subject": { "type": "text" }, "body" : { "type" : "text" }, "parent_id" : { "type" : "long" } } } } } } ``` we currently have a 'message' that can have a link to a 'parent' message. E.g. a reply would have the original message as the parent\_id. ``` PUT { "mappings": { "message": { "properties": { "subject": { "type": "text" }, "body" : { "type" : "text" }, "parent_id" : { "type" : "long" } } } } } } ``` Currently we didn't have an elasticsearch parent child join on the document as parent and child weren't allowed to be of the same type. Now with 5.6 and the drive by elastic to get rid of types we are now trying to use the new parent and child join in 5.6 which. ``` PUT { "settings": { "mapping.single_type": true }, "mappings": { "message": { "properties": { "subject": { "type": "text" }, "body" : { "type" : "text" }, "join_field": { "type" : "join", "relations": { "parent_message":"child_message" } } } } } } } ``` I know I will have to create a new index for this and then reindex everything with \_reindex but I am not quite sure how I would do that. If I index a parent\_message it is simple ``` PUT localhost:9200/testm1/message/1 { "subject": "Message 1", "body" : "body 1" } ``` For the child message I have to provide the routing to the parent: ``` PUT localhost:9200/testm1/message/3?routing=1 { "subject": "Message Reply to 1", "body" : "body 3", "join_field": { "name": "child_message", "parent": "1" } } ``` The index now has this data: ``` { "_index": "testm1", "_type": "message", "_id": "2", "_score": 1, "_source": { "subject": "Message 2", "body": "body 2" } }, { "_index": "testm1", "_type": "message", "_id": "1", "_score": 1, "_source": { "subject": "Message 1", "body": "body 1" } }, { "_index": "testm1", "_type": "message", "_id": "3", "_score": 1, "_routing": "1", "_source": { "subject": "Message Reply to 1", "body": "body 3", "join_field": { "name": "child_message", "parent": "1" } } } ``` How do I do the \_reindex now. I believe I have to manually create the join\_field and have to add \_routing to child messages. I haven't used the scripting much yet so I am struggling to get the reindex working: I've tried this: ``` { "source": { "index" : "testm" }, "dest" :{ "index" : "testmnew" }, "script" : { "lang" : "painless", "source" : "if(ctx._source.parent_id != null){ctx._routing = ctx._source.parent_id; ctx._source.join_field.name= params.name; ctx._source.join_field.parent = ctx._source.parent_id}", "params" : { "name": "child_message" } } } ``` Which doesn't work (how do you create a nested object in a script?). I have also tried this: ``` { "source": { "index" : "testm" }, "dest" :{ "index" : "testmnew" }, "script" : { "lang" : "painless", "source" : "if(ctx._source.parent_id != null){ctx._routing = ctx._source.parent_id; ctx._source.join_field= params.cjoin}", "params" : { "cjoin" :{ "name": "child_message", "parent": 1 } } } } ``` But the problem is that I cannot specify ctx.\_source.parent\_id in the params (it is hard coded to 1 now). How can I specify an id from the current document in the params? Is this the correct way of doing the reindex? Thanks Immo ---
**Author:** ![benjes](https://avatars.discourse-cdn.com/v4/letter/b/c5a1d2/32.png) [@benjes](https://discuss.elastic.co/u/benjes)\ **Post date:** [September 21, 2017, 1:03pm UTC](https://discuss.elastic.co/t/reindexing-elasticsearch-index-with-parent-and-child-relationship/101331/2 "2017-09-21T13:03:52Z")
My new index now contains these documents: ``` { "took": 2, "timed_out": false, "_shards": { "total": 5, "successful": 5, "skipped": 0, "failed": 0 }, "hits": { "total": 3, "max_score": 1, "hits": [ { "_index": "testmnew", "_type": "message", "_id": "2", "_score": 1, "_source": { "subject": "Mesage 2", "body": "Body 2" } }, { "_index": "testmnew", "_type": "message", "_id": "1", "_score": 1, "_source": { "subject": "Mesage 1", "body": "Body 1" } }, { "_index": "testmnew", "_type": "message", "_id": "3", "_score": 1, "_routing": "1", "_source": { "subject": "Mesage 3 reply to 1", "parent_id": 1, "body": "Body 3", "join_field": { "parent": 1, "name": "child_message" } } } ] } ``` } The child document with the ID 3 now has a \_routing and join\_field. When I do a search and want to include the child messages I don't get anything: ``` { "query": { "bool": { "must":[ { "match_all": {} },{ "has_child": { "type": "child_message", "query": { "match_all": {} }, "inner_hits": {} } }] } } } ``` That would indicate something went wrong (or the query is wrong but it worked on an index where I indexed the child messages by inserting them with the correct routing. ---
**Author:** ![benjes](https://avatars.discourse-cdn.com/v4/letter/b/c5a1d2/32.png) [@benjes](https://discuss.elastic.co/u/benjes)\ **Post date:** [September 22, 2017, 1:55pm UTC](https://discuss.elastic.co/t/reindexing-elasticsearch-index-with-parent-and-child-relationship/101331/3 "2017-09-22T13:55:34Z")
Okay I found the problem. You have to set the "join\_field" on the parent as well, somehow I thought to remember that you only need that on the child but that seems to be wrong. ``` { "source": { "index" : "testm" }, "dest" :{ "index" : "testmnew2" }, "script" : { "lang" : "painless", "source" : "if(ctx._source.parent_id != null){ctx._routing = ctx._source.parent_id; ctx._source.join_field= params.cjoin}else{ctx._source.join_field = params.parent_join}", "params" : { "cjoin" :{ "name": "child_message", "parent": 1 }, "parent_join" : "parent_message" } } } ``` Now I only have the problem of how to set the parent ID (use a dynamic filed in the params) ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [October 20, 2017, 1:55pm UTC](https://discuss.elastic.co/t/reindexing-elasticsearch-index-with-parent-and-child-relationship/101331/4 "2017-10-20T13:55:38Z")
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