Interpretting Shard Failure information in a search response


(Paul Smith) #1

Hey all,

just wanted to be clear on how to interpret the # shard failures during a
search, in particular a Scan type request in case it makes a difference.
Does one interpret that a search response with a # shard failures > 1 is a
'best effort' search response, and perhaps not fully accurate, or is it
simply reporting failures ES has managed to recover from and return a
full/complete response ?

I guess for my case, if I'm really needing the response to be accurate, that
any shard failure count > 0 should require retrying the request (with
bailout/backoff/whatever) built in?

tah,

Paul


(Shay Banon) #2

Heya,

When you get shard failures, it means that the search failed to execute on
the respective shards (on all those shard replicas, as they are
automatically retried) that are reported. The result of the search will
include hits from the rest (non failed) shards.

On Thu, Oct 6, 2011 at 1:45 PM, Paul Smith tallpsmith@gmail.com wrote:

Hey all,

just wanted to be clear on how to interpret the # shard failures during a
search, in particular a Scan type request in case it makes a difference.
Does one interpret that a search response with a # shard failures > 1 is a
'best effort' search response, and perhaps not fully accurate, or is it
simply reporting failures ES has managed to recover from and return a
full/complete response ?

I guess for my case, if I'm really needing the response to be accurate,
that any shard failure count > 0 should require retrying the request (with
bailout/backoff/whatever) built in?

tah,

Paul


(Paul Smith) #3

On 7 October 2011 01:54, Shay Banon kimchy@gmail.com wrote:

Heya,

When you get shard failures, it means that the search failed to execute
on the respective shards (on all those shard replicas, as they are
automatically retried) that are reported. The result of the search will
include hits from the rest (non failed) shards.

ok, so any shard failure is effectively a compromised search, you can't
trust the results. thanks.

Paul


(system) #4