# Low performance

**URL:** <https://discuss.elastic.co/t/low-performance/139574>\
**Category:** Elasticsearch\
**Created:** [July 11, 2018, 1:16pm UTC](https://discuss.elastic.co/t/low-performance/139574 "2018-07-11T13:16:56Z")\
**Posts on this page:** 8\
**Page:** 1

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**Author:** ![shanmukha1499](https://avatars.discourse-cdn.com/v4/letter/s/258eb7/32.png) [@shanmukha1499](https://discuss.elastic.co/u/shanmukha1499)\
**Post date:** [July 11, 2018, 1:16pm UTC](https://discuss.elastic.co/t/low-performance/139574/1 "2018-07-11T13:16:56Z")

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Hi

I have elastic cluster of 2 nodes with same hardware specifications  
hardware specs of each machine:  
RAM:16G  
No.of Cpu's : 2

node1- master+data  
node2- master+data

discovery.zen.minimum\_master\_nodes: 1

Here are details of index:

No.of shards - 5  
No.of replicas- 1

index-size - 1.3G and has nearly 6 lac documents(only primary shards,without replicas, I am not sure why replicas are in unassigned state), which will increase at speed of ~6k documents per day.

I have a dashboard of nearly 12 visualizations, all are PIE charts and its taking more time load the page.(nearly 10-13 secs)

Are the above mentioned hardware resources are good enough for my requirement or any change in shard, replica count to get a better performance?

Thanks in advance

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**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\
**Post date:** [July 11, 2018, 1:41pm UTC](https://discuss.elastic.co/t/low-performance/139574/2 "2018-07-11T13:41:49Z")

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> [@shanmukha1499](#):
>
> node1- master+data  
> node2- master+data
> 
> discovery.zen.minimum\_master\_nodes: 1

As you have 2 master-eligible nodes, `discovery.zen.minimum_master_nodes` should be set to `2` as per [these guidelines](https://www.elastic.co/guide/en/elasticsearch/reference/5.6/modules-node.html#split-brain).

> [@shanmukha1499](#):
>
> I have elastic cluster of 2 nodes with same hardware specifications  
> hardware specs of each machine:  
> RAM:16G  
> No.of Cpu's : 2

Are these virtual machines? What kind of storage do you have? Are you indexing at the same time you are querying?

How much heap have you got assigned? Which Elasticsearch version are you using?

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<div class="post-metadata">

**Author:** ![shanmukha1499](https://avatars.discourse-cdn.com/v4/letter/s/258eb7/32.png) [@shanmukha1499](https://discuss.elastic.co/u/shanmukha1499)\
**Post date:** [July 11, 2018, 2:21pm UTC](https://discuss.elastic.co/t/low-performance/139574/3 "2018-07-11T14:21:21Z")

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I put discovery.zen.minimum\_master\_nodes: 2, I saw the same performance  
yes they are virtual machines, I think the resources(cpus) are shared  
How much heap have you got assigned? - I am not sure how to get this value,  
How much heap have you got assigned? - can you help me in getting that will be great  
Are you indexing at the same time you are querying? - I didn't get your question, can you elaborate?  
Which Elasticsearch version are you using? - 6.1.2  
Storage - is an nfs mount

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**Author:** ![Ant](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/ant/32/33267_2.png) [@Ant](https://discuss.elastic.co/u/Ant)\
**Post date:** [July 11, 2018, 2:52pm UTC](https://discuss.elastic.co/t/low-performance/139574/4 "2018-07-11T14:52:45Z")

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sign in to Kibana ([http://machineip:5601](http://machineip:5601) unless you configured it otherwise) , under monitoring go to nodes, open each node and it will tell you the max heap size in there on the JVM heap chart

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<div class="post-metadata">

**Author:** ![shanmukha1499](https://avatars.discourse-cdn.com/v4/letter/s/258eb7/32.png) [@shanmukha1499](https://discuss.elastic.co/u/shanmukha1499)\
**Post date:** [July 12, 2018, 6:47am UTC](https://discuss.elastic.co/t/low-performance/139574/5 "2018-07-12T06:47:46Z")

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ps -ef| grep elastic  
root 9886 1 7 06:26 ? 00:01:18 /data/elasticsearch/jdk1.8.0\_131//bin/java **-Xms1g -Xmx1g** -XX:+UseConcMarkSweepGC -XX:CMSInitiatingOccupancyFraction=75 -XX:+UseCMSInitiatingOccupancyOnly -XX:+AlwaysPreTouch -server -Xss1m -Djava.awt.headless=true -Dfile.encoding=UTF-8 -Djna.nosys=true -XX:-OmitStackTraceInFastThrow -Dio.netty.noUnsafe=true -Dio.netty.noKeySetOptimization=true -Dio.netty.recycler.maxCapacityPerThread=0 -Dlog4j.shutdownHookEnabled=false -Dlog4j2.disable.jmx=true -XX:+HeapDumpOnOutOfMemoryError -Des.path.home=/data/elasticsearch/elasticsearch-6.1.2 -Des.path.conf=/data/elasticsearch/elasticsearch-6.1.2/config -cp /data/elasticsearch/elasticsearch-6.1.2/lib/\* org.elasticsearch.bootstrap.Elasticsearch -d

-Xms1g -Xmx1g

as per [https://www.elastic.co/guide/en/elasticsearch/reference/current/heap-size.html](https://www.elastic.co/guide/en/elasticsearch/reference/current/heap-size.html)

My heap size is 1G

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<div class="post-metadata">

**Author:** ![Christian\_Dahlqvist](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/christian_dahlqvist/32/4617_2.png) [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)\
**Post date:** [July 12, 2018, 7:07am UTC](https://discuss.elastic.co/t/low-performance/139574/6 "2018-07-12T07:07:01Z")

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> [@shanmukha1499](#):
>
> Storage - is an nfs mount

NFS storage is not recommended as it can be very slow and also cause corruption.

> [@shanmukha1499](#):
>
> I put discovery.zen.minimum\_master\_nodes: 2, I saw the same performance

This is not for improving performance, but rather to give better resilience and avoid data loss.

> [@shanmukha1499](#):
>
> My heap size is 1G

That is quite a small heap, but should be sufficient given the amount of data you have. If you see long or frequent GC being reported in the logs you may want to increase this, but keep it at or below 50% of RAM.

> [@shanmukha1499](#):
>
> yes they are virtual machines, I think the resources(cpus) are shared

Make sure that you have access to the resources you think you have. I would recommend installing monitoring to get a good view of how the cluster performs.

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<div class="post-metadata">

**Author:** ![shanmukha1499](https://avatars.discourse-cdn.com/v4/letter/s/258eb7/32.png) [@shanmukha1499](https://discuss.elastic.co/u/shanmukha1499)\
**Post date:** [July 12, 2018, 11:14am UTC](https://discuss.elastic.co/t/low-performance/139574/7 "2018-07-12T11:14:36Z")

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Actually the storage is ext4, not nfs

I didn't see any log regarding GC, I see only one log that too in one node  
[2018-07-12T06:29:23,957][INFO][o.e.m.j.JvmGcMonitorService] [node-1] [gc][201] overhead, spent [260ms] collecting in the last [1s]

Anyway I set Heap to 4G

still its taking 14 secs to load the dashboard, after refreshing it several times it was loading bit early nearly in 7 secs

by the way my index has 259 fields and the count may increase slowly, anything can be done here?  
And some fields are like nested(ex: level1.level2.level3 and level1.level2.level3.keyword)  
I have two fields per key(keyword is coming by default)

I am attaching screenshots of my cluster overview in normal time and during the time of dashboard loading(used cerebro monitoring tool)  
PFA

 ![while_loading_dashboard](https://us1.discourse-cdn.com/elastic/original/3X/3/b/3bcc9168775e88160e8297135b2e02dd01ada4f6.png) ![normal](https://us1.discourse-cdn.com/elastic/original/3X/1/2/12c217051ca05312fd806d3a06dbcb732330d359.png)

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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:** [August 9, 2018, 11:14am UTC](https://discuss.elastic.co/t/low-performance/139574/8 "2018-08-09T11:14:39Z")

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