Too many shards may result in querying performance.
daveey <[email protected]>编写：
>I just upgraded to ES 1.0.1 from ES 0.9.2 and am seeing huge performance
>problems.
>
>
>I traced them to what I think is the post_filter.
>
>
>Here is the query that we used to run against ES 0.9.2
>
>
>
>{
> filter": {
>
> "and": [
>
> {
>
> "terms": {
>
> "index_ids": [
>
> 2134616789944
>
> ]
>
> }
>
> },
>
> {
>
> "or": [
>
> {
>
> "term": {
>
> "trashed_at": 0
>
> }
>
> },
>
> {
>
> "not": {
>
> "exists": {
>
> "field": "trashed_at"
>
> }
>
> }
>
> }
>
> ]
>
> }
>
> ]
>
> }
>
>}
>
>
>This used to take the 0.9 cluster about 150ms to execute
>
>The same query takes about 2.5s for the 1.0 cluster.
>
>I rewrote it to conform to my understanding of the changes in 1.0, using a
>filtered query, however, that didn't help.
>
>I then tried to figure out which parts were slow. I now have the following
>query
>
>{
> "query": {
>
> "filtered": {
>
> "query": {
>
> "match_all": {}
>
> },
>
> "filter": {
>
> "terms": {
>
> "index_ids": [
>
> 2134616789944
>
> ]}
>
> }
>
> }
>
> },
>
> "post_filter": {
>
> "or": [
>
> {"term": {"trashed_at": 0}},
>
> {"not": {"exists": {"field": "trashed_at"}}}
>
> ]}
>
>}
>
>
>It takes 2.5 s and returns 34 hits. However, removing the "post_filter" clause:
>
>{
> "query": {
>
> "filtered": {
>
> "query": {
>
> "match_all": {}
>
> },
>
> "filter": {
>
> "terms": {
>
> "index_ids": [
>
> 2134616789944
>
> ]
>
> }
>
> }
>
> }
>
> }
>
>}
>
>
>Makes it take 50ms and return 34 results.
>
>My conclusion is that it's taking 2.5 seconds to filter 34 results, and that's
>confusing.
>
>The cluster uses 3 machines, 50 shards, 2 replicas per shard. This means that
>each machine has the entire copy of the index. We use the ?routing= parameter,
>and are always hitting a single shard for the query.
>
>Help?
>
>
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