Es circuit breaker, the JVM heap memory is not enough to load data for the current query, so it will report data too large, and the request is blown.
1、 Cause of occurrence
There are too many batch import data or too many query data, which is more frequent
When the cluster status is yellow or red, analyze the reason:
GET _ cluster/allocation/explain
2、 Periodically clean up the cache
The regular memory cleaning can not ensure the availability of the server. However, if the memory is not enough, the ES can increase the availability of the service.
Although the query may be slow, it is much better than directly reporting an error, unable to query and unsuccessful data saving
1. Clean cache method
delete data acquisition Indexes Cache: POST / collect_ data*/_ cache/clear
monitor Field cache: get /_ stats/fielddata?fields=*
2. Restart cluster node
If the cleanup cache is invalid_ Cache/clear, then restart.
If it occurs frequently The data too large is abnormal. I think it can be reduced again indices.fielddata.cache.size This setting. Let it clean up the cache as soon as possible.
Increase at the same time The available memory of ES, and the limit size corresponding to the available memory: i.e indices.breaker..limit
Through monitoring, find the cause of the problem: get /_ cluster/stats?pretty
3、 Optimize query
1. Increase server memory and ES cluster
When there is too much index data and the server memory is too small, even if the cache is cleaned regularly, the _ In cache/clear, there is still an exception that triggers the fuse. At this time, we can only consider upgrading the memory and expanding the ES cluster.
2. Avoid using Index name*
This method is similar to select * from table
For example, I generate an index every year or every month user_ 2020, and user_ two thousand and nineteen
When querying, I use the index as follows: user* This will definitely affect the query performance,
If a complex aggregation statement, es will aggregate all indexes beginning with user, which must occupy a lot of memory.
At this time, you can consider whether it is the query statement usage of ES?Check and optimize
More tuning References: https://blog.csdn.net/andy_ only/article/details/98172044
3. JVM configuration uses G1 garbage collector
