# Data transfer between Elasticsearch Data Nodes

**URL:** <https://discuss.elastic.co/t/data-transfer-between-elasticsearch-data-nodes/224106>\
**Category:** Elasticsearch\
**Created:** [March 18, 2020, 12:20pm UTC](https://discuss.elastic.co/t/data-transfer-between-elasticsearch-data-nodes/224106 "2020-03-18T12:20:59Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![rupam](https://avatars.discourse-cdn.com/v4/letter/r/977dab/32.png) [@rupam](https://discuss.elastic.co/u/rupam)\
**Post date:** [March 18, 2020, 12:20pm UTC](https://discuss.elastic.co/t/data-transfer-between-elasticsearch-data-nodes/224106/1 "2020-03-18T12:20:59Z")

</div>

Hi Everyone,

In my deployment, I have 3 node elasticsearch cluster in kubernetes environment and 5 clients are writing data to this cluster at rate of ~7MB/s per elasticsearch data node and NO READ operation is performed. Below are the few configurations Elasticsearch configuration details. Two mount points are configured in two different disks for storing the data, also number of shards is 6 and there is no replication. What we have observed that there is ~10MB/s data transfer is happening between the elasticsearch data nodes. So, could someone please explain about this internode data transfer and is there a way to reduce it. Thanks.

# iftop -B output:

```
metrics-datastore-0.metrics-datastore.a10harmony.svc.cluster.local => metrics-datastore-1.metrics-datastore.a10harmony.svc.cluster.local 12.2MB 15.4MB 14.4MB
                                                                     <= 11.3MB 14.1MB 14.1MB
metrics-datastore-0.metrics-datastore.a10harmony.svc.cluster.local => metrics-datastore-2.metrics-datastore.a10harmony.svc.cluster.local 21.4MB 15.2MB 14.4MB
                                                                     <= 21.9MB 13.9MB 13.9MB

```

# ES Version details:

bash-4.1# curl -XGET 'localhost:9200'  
{  
"name" : "metrics-datastore-0",  
"cluster\_name" : "metrics-datastore",  
"cluster\_uuid" : "cNKU0p\_2TVGzN350m3KXKw",  
"version" : {  
"number" : "6.6.0",  
"build\_flavor" : "default",  
"build\_type" : "tar",  
"build\_hash" : "a9861f4",  
"build\_date" : "2019-01-24T11:27:09.439740Z",  
"build\_snapshot" : false,  
"lucene\_version" : "7.6.0",  
"minimum\_wire\_compatibility\_version" : "5.6.0",  
"minimum\_index\_compatibility\_version" : "5.0.0"  
},  
"tagline" : "You Know, for Search"  
}

# ES settings:

index.number\_of\_replicas": 0,  
index.number\_of\_shards: 6,  
index.refresh\_interval: 30s,  
index.translog.durability: async,  
index.translog.flush\_threshold\_size: 1g,  
index.translog.sync\_interval: 10s,  
index.unassigned.node\_left.delayed\_timeout: 10m,  
index.mapping.total\_fields.limit: 3000

path.data: /data/elasticsearch/data,/data2/elasticsearch/data  
path.logs: /logs/elasticsearch,/logs2/elasticsearch

discovery.zen.fd.ping\_interval: 10s  
discovery.zen.fd.ping\_retries: 5  
discovery.zen.fd.ping\_timeout: 120s  
gateway.recover\_after\_master\_nodes: 2  
gateway.recover\_after\_data\_nodes: 2  
gateway.recover\_after\_time: 5m  
gateway.expected\_data\_nodes: 3  
gateway.expected\_master\_nodes: 3  
gateway.expected\_nodes: 6  
http.cors.enabled: false  
indices.fielddata.cache.size: 10%  
indices.memory.index\_buffer\_size: 30%  
thread\_pool.write.queue\_size: 2000  
network.bind\_host: , _local_  
network.publish\_host:   
logger.gateway: TRACE

---

<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:** [April 15, 2020, 12:21pm UTC](https://discuss.elastic.co/t/data-transfer-between-elasticsearch-data-nodes/224106/2 "2020-04-15T12:21:03Z")

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