Cannot Parse The "search_phase_execution_exception" Into Go Structure *elastic.Error And Get The Root Cause - elasticsearch

Question

My department uses the olivere elastic v7.0.26 as ElasticSearch Client,sometimes our front-end system returns some errormsg such as "Error 400 (Bad Request): all shards failed [type=search_phase_execution_exception]" but doesn't have any other useful msg to help troubleshooting,so I've searched GitHub about parsing errors to *elastic.Error and codes are just like this:
if err != nil {
log.WithFields(ctx, log.Fields{}).WithError(err).Warn("list query es error")
if ex, ok := err.(*elastic.Error); ok {
log.WithFields(ctx, log.Fields{"query": query, "status": ex.Status, "detail": ex.Details}).WithError(ex).Warnf("list query es err")
}
return res, err
}
But the strange thing happened is "list query es error" was printed on our log system but the next log "list query es err" didn't,i've used deep-paging (large from+size) to check the log,it works and print the elastic error such as root cause so i can get the max_result_window tips..But it returns a unparsing error which is returned as the search_phase_execution_exception error,the company code is not allowed to paste to the open-sourcing website,and I just wanna know what error can make elasticsearch returns the search_phase_execution_exception and the errcode 400?Really appreciate your help!
same to above description,but the point I need to supple is that the problem is not always happened,so I can exclude the index mapping field type error such as "text/keyword",just wanna get the whole error/exceptions elasticsearch can return,but I cannot find the relative documentions on elastic guide,that's ok if u can provide the guide/doc about this

Answer 1

uhh it seems like a joke XD,I've never learned about some troubleshooting technique,but after I asked this question,I realized that I can get the ElasticSearch server log,so I asked our company's SRE and got the log,it's a error about terms query exceed maximum,and the reason caused is our RPC interface return a exceptional result about nil data redis set key,it will be a big-key problem,but we found this and fix it.