TotalShardsPerNode Index setting VS cluster setting

[JonathanAaron]

Settings in question:
cluster.routing.allocation.total_shards_per_node
index.routing.allocation.total_shards_per_node

Actual Question:
Lets say I have multiple indices and I set index.routing.allocation.total_shards_per_node to 5.
Does that block other indices from having shards on the node?

Scenario:
Index A has index.routing.allocation.total_shards_per_node: 5
Index B has index.routing.allocation.total_shards_per_node: 5

If Node 1 has 5 shards from index A on it can it accept any from index B?

[spinscale (Alexander Reelsen)]

Hey,

should work, but this is one of the classic examples, where quick testing beats guessing.
You can easily test this, using the following snippet and tweaking the values

DELETE _all

PUT _cluster/settings
{
  "transient": {
    "cluster.routing.allocation.total_shards_per_node" : 1
  }
}

PUT a
{
  "settings": {
    "index.routing.allocation.total_shards_per_node" : 1,
    "number_of_shards": 2
  }
}

PUT b
{
  "settings": {
    "index.routing.allocation.total_shards_per_node" : 1,
    "number_of_shards": 2
  }
}

# this will show if the shards have been assigned or not
GET _cat/shards

hope this helps

--Alex

[JonathanAaron]

Cool I'll test it out. Thanks