# Rebalancing of shards
**URL:** https://discuss.elastic.co/t/rebalancing-of-shards/13459
**Category:** Elasticsearch
**Created:** [September 4, 2013, 12:43pm UTC](https://discuss.elastic.co/t/rebalancing-of-shards/13459 "2013-09-04T12:43:34Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Ranjith\_Venkatesan](https://discuss.elastic.co/u/Ranjith_Venkatesan)
#### Post date: [September 4, 2013, 12:43pm UTC](https://discuss.elastic.co/t/rebalancing-of-shards/13459/1 "2013-09-04T12:43:34Z")
Hi,
We are going to use ES in production soon. I demonstrated a scenario. Let me explain that first. I first created 50 indices(say 1 to 50). After shards got allocated, i created another 50 indices(say 51 to 100). Indices got created successfully. But in logs i noticed a strange behavior.
When i am creating 50 indices (51 to 100), it re-balances shard created during first time(say shard 2 of index 12). I have posted part of log below
_[2013-09-04 18:01:18,101][DEBUG][indices.recovery] [Magnum, Moses] [99][4] recovery completed from [La Lunatica][MuMeUDf7TaKmOiAuEQ05sA][inet[/172.18.97.193:9300]], took[51ms]
phase1: recovered\_files [1] with total\_size of [71b], took [44ms], throttling\_wait [0s]
: reusing\_files [0] with total\_size of [0b]
phase2: start took [2ms]
: recovered [0] transaction log operations, took [0s]
phase3: recovered [0] transaction log operations, took [0s]
[2013-09-04 18:01:18,357][DEBUG][indices.recovery] [Magnum, Moses] [12][2] recovery completed from [Mad Jim Jaspers][u9ZwGfrvSTaQSKJmYZ6W9w][inet[/172.18.97.193:9303]], took[50ms]
phase1: recovered\_files [1] with total\_size of [71b], took [16ms], throttling\_wait [0s]
: reusing\_files [0] with total\_size of [0b]
phase2: start took [14ms]
: recovered [0] transaction log operations, took [19ms]
phase3: recovered [0] transaction log operations, took [1ms]_
Is rebalancing necessary during index creation? Seems to be an extra overhead. I referred many docs, but none explain how rebalancing will be done. Please explain how and when re-balancing will be done in ES ?
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 6, 2017, 2:18am UTC](https://discuss.elastic.co/t/rebalancing-of-shards/13459/2 "2017-07-06T02:18:16Z")