# Zombie Search Tasks on 5.4.0

**URL:** <https://discuss.elastic.co/t/zombie-search-tasks-on-5-4-0/129554>\
**Category:** Elasticsearch\
**Created:** [April 25, 2018, 7:40pm UTC](https://discuss.elastic.co/t/zombie-search-tasks-on-5-4-0/129554 "2018-04-25T19:40:34Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![umahida](https://avatars.discourse-cdn.com/v4/letter/u/c4cdca/32.png) [@umahida](https://discuss.elastic.co/u/umahida)\
**Post date:** [April 25, 2018, 7:40pm UTC](https://discuss.elastic.co/t/zombie-search-tasks-on-5-4-0/129554/1 "2018-04-25T19:40:34Z")

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Hi there,  
I have a situation were when searches are done or timedout and the cluster gathers search tasks which are visible by /\_cat/tasks | grep search.  
When i see the details via /\_task?actions=\*search&detailed i see they

- dont have parent task id (expected since the origin http search requests is timedout)
- type : transport
- indices:data/read/search  
These pile up and lead to excessive search timeouts. Bouncing the node fixes the issue.  
I am not able to pin down if these zombie task are causing search timeouts or initializing shards due to cluster instability are causing increasing search timeouts.  
I am expected the zombie tasks should not pile up at-least.

In logs when i tried trace i do see a possible co-relation (could be red herring) that the tasks are targeting indexes which be recovered or de-allocated from the node on which the task is left behind.

I see messages like  
[2018-04-25T19:18:53,013][TRACE][o.e.t.TaskManager] [host3-1] register 106886 [transport] [indices:data/read/search] [indices[xx-2018.04.09], types[], search\_type[QUERY\_THEN\_FETCH], source[{"size":0,"query":{"range":{"@timestamp":{"from":"2018-03-25T05:13:09.405432","to":"2018-04-24T05:13:09.405432","include\_lower":true,"include\_upper":false,"time\_zone":"UTC","boost":1.0}}},"sort":[{"@timestamp":{"order":"desc","unmapped\_type":"date"}}]}]]  
&  
NEITHER unregister task for id:  
on the node where the zombie task is piled up for the zombie task IDs but still the tasks show up on task management API

Any possible pointers ? possible bug ?

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\
**Post date:** [May 23, 2018, 7:40pm UTC](https://discuss.elastic.co/t/zombie-search-tasks-on-5-4-0/129554/2 "2018-05-23T19:40:34Z")

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Closed on May 23, 2018, 7:40pm UTC

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