Elastic search in Unravel failing with out of memory - elasticsearch

Out of memory*
Elastic search service frequently going down.
It consuming more resource and running out of memory.

Issue with heap memory for elastic search.
Update below value:
 Go to /installer/templates/elasticsearch/start.sh.template
Increase HEAP_MB value

Related

Elastic search kubernetes Sudden rise in data disk usage

Deployed elastic search Kubernetes in GKE. With 2GB memory and 1GB persistence disk.
We got an error out of storage exception. After that, we have Increased to 2GB on the next day itself it reached 2GB, but we haven’t run any big queries. Then again we have increased the persistence disk size to 10 GB. After that, there is no increase in the data persistence disk storage.
On further analysis, we have found total Indices take 20MB of memory unable to what are the data in the disk.
Used elastic search nodes stats API to get the details on disk and node statistics.
I am unable to find the exact reason why memory exceeds and what are the data in the disk. Also, suggest ways to prevent this future.
It is continuously receiving data and based on your config it creates multiple copies of indices and may create a new index daily. Check the config file.
if the elasticsearch cluster fails each time it creates a backup of data so you may need to delete old backups before restarting the cluster.

Does decrease elasticsearch heap size could help improve search performance?

From 01-13, search performance has slowed down, maybe some metrics has reached a critical value, e.g the index doc count or store size.
From official document, I got
Elasticsearch heavily relies on the filesystem cache in order to make search fast. In general, you should make sure that at least half the available memory goes to the filesystem cache so that Elasticsearch can keep hot regions of the index in physical memory.
And now the maxed used heap is 11.72GB and elasticsearch app specified 16G (-Xms16g -Xmx16g)
So if I changed elasticsearch heap size to 12GB(-Xms12g -Xmx12g), does filesystem cache could used more memory and the search performance could improve?

How to change elastic search heap size in elastic cloud?

I am using 14 trial account of elastic search. This account showing me I have a 4.6GB heap size. I want to reduce my heap size to 2GB so how I can reduce this. I have checked the way of changing the heap size using the following options:
export ES_HEAP_SIZE=2g or
ES_JAVA_OPTS="-Xms2g -Xmx2g" ./bin/elasticsearch
But How I can reduce the heap size using one of the above option in the elastic cloud?
Since Elastic Cloud is a managed service, end users do not have access to the backend master and data nodes in the cluster. Unfortunately, you cannot change the heap size setting of an Elastic Cloud Elasticsearch cluster. You can however scale down your cluster so that the heap memory allocated also reduces. Alternatively, you could try emailing Elastic support at support#elastic.co and ask if they can change the heap size for you but I highly doubt that level of customization is offered for Elastic Cloud service.

Elasticsearch config tweaking with limited memory

I have following scenario:
A single machine with 32GB of ram runs Elasticsearch 2.4, there is one index with 5 shards that is 25gb in size.
On that index we are constantly indexing new data, plus doing full-text search queries that check about 95% documents - no aggregations. The instance generates a lot of CPU load - there is no swapping.
My question is: how should I tweak elasticsearch memory usage? (I don't have an option to add another machine at this moment)
Should I assign more memory to ES HEAP like 25GB (going over 50% memory that readme advises to not do do), or should I assign minimal HEAP like 1GB-2GB and assume Lucene will cache all the index in memory since its full-text searches?
Right now 50% of server memory so 16GB in this case seems to work best for us.

Elasticsearch: What if size of index is larger than available RAM?

Assuming a single machine system with an in-memory indexing schema.
I am not able to find this info in ES docs. Does ES start swapping out the overflowing data, loads it when needed and continue working or it gives an error?
In-memory indices provide better performance at the cost of limiting the index size to the amount of available physical memory.
Via the 1.7 documentation. Memory stores are no longer available in 2.0+.
Under the hood it uses the Lucene RAMDirectory, which will just consume RAM (and eventually swap) until either you hit Java heap limits and ES crashes with out-of-memory errors, or the system gives up and oomkills the Elasticsearch process. Don't use in-memory indexes for large indexes, or for any situation where persistence is important.

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