# Bulk indexing rejected threads
**URL:** https://discuss.elastic.co/t/bulk-indexing-rejected-threads/223679
**Category:** Elasticsearch
**Created:** [March 16, 2020, 1:29am UTC](https://discuss.elastic.co/t/bulk-indexing-rejected-threads/223679 "2020-03-16T01:29:57Z")
**Posts on this page:** 15
**Page:** 1
### Author:  [@adrian\_luighi](https://discuss.elastic.co/u/adrian_luighi)
#### Post date: [March 16, 2020, 1:29am UTC](https://discuss.elastic.co/t/bulk-indexing-rejected-threads/223679/1 "2020-03-16T01:29:58Z")
Hello, I am pretty new to elasticsearch I made my project and everything works really well except bulk indexing. The problem is I am getting alot of rejected write threads. I looked up thread pool and I got this:
node\_name write 0 0 121044
My current configuration of index is 100 primary shards and 0 replicas. I am running this on single node(32gb heap size, database is stored on NVMe storage,8core/16thread AMD cpu).
my index:
{
"mapping": {
"\_doc": {
"properties": {
"hash": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore\_above": 256
}
}
},
"uri": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore\_above": 256
}
}
},
"path": {
"type": "text",
"fields": {
"keyword": {
"type": "keyword",
"ignore\_above": 256
}
}
}
}
}
}
}
hash- 600-700 character string(the field I am searching using query\_string)
url/path - 100 characters max.
each document is around 1-1.2kb, I will be having 800 million documents ~915GB data.
I am using NEST to do the BULK index with settings:
BackOffRetries 10
BackOffTime 5 seconds
MaxDegreeOfParallelism 5
Size 5000
With my experience I couldn't resolve it. I would appreciate if someone points me to right the direction 😃
---
### Author:  [@warkolm](https://discuss.elastic.co/u/warkolm)
#### Post date: [March 16, 2020, 1:33am UTC](https://discuss.elastic.co/t/bulk-indexing-rejected-threads/223679/2 "2020-03-16T01:33:32Z")
> [@adrian\_luighi](#):
>
> My current configuration of index is 100 primary shards and 0 replicas. I am running this on single node(32gb heap size, database is stored on NVMe storage,8core/16thread AMD cpu).
That's way too many shards, why did you pick this?
---
### Author:  [@adrian\_luighi](https://discuss.elastic.co/u/adrian_luighi)
#### Post date: [March 16, 2020, 1:53am UTC](https://discuss.elastic.co/t/bulk-indexing-rejected-threads/223679/3 "2020-03-16T01:53:42Z")
I read article that I needed 1 shard per 5mil documents
EDIT: how many shards should I use for my use case?
---
### Author:  [@warkolm](https://discuss.elastic.co/u/warkolm)
#### Post date: [March 16, 2020, 2:00am UTC](https://discuss.elastic.co/t/bulk-indexing-rejected-threads/223679/4 "2020-03-16T02:00:00Z")
Not sure what article that is, but I'd suggest it's not accurate, and you're wasting resources with such a large shard count.
Aim for 30-50GB per shard instead.
---
### Author:  [@adrian\_luighi](https://discuss.elastic.co/u/adrian_luighi)
#### Post date: [March 16, 2020, 2:04am UTC](https://discuss.elastic.co/t/bulk-indexing-rejected-threads/223679/5 "2020-03-16T02:04:55Z")
Alright understood I will reduce shard amount to 35. One small question tho, do I need replicas?
---
### Author:  [@warkolm](https://discuss.elastic.co/u/warkolm)
#### Post date: [March 16, 2020, 2:06am UTC](https://discuss.elastic.co/t/bulk-indexing-rejected-threads/223679/6 "2020-03-16T02:06:34Z")
You only have a single node cluster, so it's not really relevant if you have them or not 🙂
---
### Author:  [@adrian\_luighi](https://discuss.elastic.co/u/adrian_luighi)
#### Post date: [March 16, 2020, 2:21am UTC](https://discuss.elastic.co/t/bulk-indexing-rejected-threads/223679/7 "2020-03-16T02:21:13Z")
Actually reducing shard amount resolved my issue. I am no longer getting rejected writes and I've indexed ~500 thousand document right now. Will be updating this thread after a day or two after testing. Thank you.
---
### Author:  [@adrian\_luighi](https://discuss.elastic.co/u/adrian_luighi)
#### Post date: [March 16, 2020, 5:35am UTC](https://discuss.elastic.co/t/bulk-indexing-rejected-threads/223679/8 "2020-03-16T05:35:52Z")
It still happens but it happens way less times. Where can I see logs so I can see whats happening?
---
### Author:  [@warkolm](https://discuss.elastic.co/u/warkolm)
#### Post date: [March 16, 2020, 6:47am UTC](https://discuss.elastic.co/t/bulk-indexing-rejected-threads/223679/9 "2020-03-16T06:47:03Z")
Check Monitoring to see what is happening, are you hitting disk or CPU limits?
---
### Author:  [@adrian\_luighi](https://discuss.elastic.co/u/adrian_luighi)
#### Post date: [March 16, 2020, 8:05am UTC](https://discuss.elastic.co/t/bulk-indexing-rejected-threads/223679/10 "2020-03-16T08:05:46Z")
I barely saturate CPU and storage(raid 0 nvme). I can't setup HeartBeat I get the error:
[invalid\_index\_name\_exception] Invalid index name [_security], must not start with '_', '-', or '+', with { index\_uuid="_na_" & index="\_security" }: Check the Elasticsearch Monitoring cluster network connection or the load level of the nodes.
---
### Author:  [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)
#### Post date: [March 16, 2020, 8:37am UTC](https://discuss.elastic.co/t/bulk-indexing-rejected-threads/223679/11 "2020-03-16T08:37:28Z")
Are you indexing new documents only or are you also performing updates?
---
### Author:  [@adrian\_luighi](https://discuss.elastic.co/u/adrian_luighi)
#### Post date: [March 16, 2020, 8:54am UTC](https://discuss.elastic.co/t/bulk-indexing-rejected-threads/223679/12 "2020-03-16T08:54:46Z")
before I bulk index I set update interval to -1 then bulk index with parameters mentioned above and after it's done I set back interval to 1s thats it. indexing MAY happen in parallel.
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### Author:  [@Christian\_Dahlqvist](https://discuss.elastic.co/u/Christian_Dahlqvist)
#### Post date: [March 16, 2020, 9:33am UTC](https://discuss.elastic.co/t/bulk-indexing-rejected-threads/223679/13 "2020-03-16T09:33:12Z")
That does not answer my question.
---
### Author:  [@adrian\_luighi](https://discuss.elastic.co/u/adrian_luighi)
#### Post date: [March 16, 2020, 9:41am UTC](https://discuss.elastic.co/t/bulk-indexing-rejected-threads/223679/14 "2020-03-16T09:41:55Z")
What you mean in updates? if you mean updating existing ones no.
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [April 13, 2020, 9:42am UTC](https://discuss.elastic.co/t/bulk-indexing-rejected-threads/223679/15 "2020-04-13T09:42:01Z")
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