If the ping request handler is taking too long, and the server is not recovering automatically, there is not much you can do automatically on that server. You have to intervene manually, and restart Solr on that node.
First of all: the ping is just an internal check. If it takes too long to respond, the requester (i.e. the script calling it), should stop the request, and mark that node as problematic. If there are for example memory problems every subsequent request will only enhance the problem, and Solr cannot recover from that. > On 5 Aug 2019, at 06:15, dinesh naik <dineshkumarn...@gmail.com> wrote: > > Thanks john,Erick and Furknan. > > I have already defined the ping request handler in solrconfig.xml as below: > <requestHandler name="/admin/ping" class="solr.PingRequestHandler"> <lst > name="invariants"> <str name="qt">/select</str><!-- handler to delegate to > --> <str name="q">_root_:abc</str> </lst> </requestHandler> > > My question is regarding the custom query being used. Here i am querying > for field _root_ which is available in all of my cluster and defined as a > string field. The result for _root_:abc might not get me any match as > well(i am ok with not finding any matches, the query should not be taking > 10-15 seconds for getting the response). > > If the response comes within 1 second , then the core recovery issue is > solved, hence need your suggestion if using _root_ field in custom query is > fine? > > > On Mon, Aug 5, 2019 at 2:49 AM Furkan KAMACI <furkankam...@gmail.com> wrote: > >> Hi, >> >> You can change invariants i.e. *qt* and *q* of a *PingRequestHandler*: >> >> <requestHandler name="/admin/ping" class="solr.PingRequestHandler"> >> <lst name="invariants"> >> <str name="qt">/search</str><!-- handler to delegate to --> >> <str name="q">some test query</str> >> </lst> >> </requestHandler> >> >> Check documentation fore more info: >> >> https://lucene.apache.org/solr/7_6_0//solr-core/org/apache/solr/handler/PingRequestHandler.html >> >> Kind Regards, >> Furkan KAMACI >> >> On Sat, Aug 3, 2019 at 4:17 PM Erick Erickson <erickerick...@gmail.com> >> wrote: >> >>> You can also (I think) explicitly define the ping request handler in >>> solrconfig.xml to do something else. >>> >>>> On Aug 2, 2019, at 9:50 AM, Jörn Franke <jornfra...@gmail.com> wrote: >>>> >>>> Not sure if this is possible, but why not create a query handler in >> Solr >>> with any custom query and you use that as ping replacement ? >>>> >>>>> Am 02.08.2019 um 15:48 schrieb dinesh naik <dineshkumarn...@gmail.com >>> : >>>>> >>>>> Hi all, >>>>> I have few clusters with huge data set and whenever a node goes down >> its >>>>> not able to recover due to below reasons: >>>>> >>>>> 1. ping request handler is taking more than 10-15 seconds to respond. >>> The >>>>> ping requesthandler however, expects it will return in less than 1 >>> second >>>>> and fails a requestrecovery if it is not responded to in this time. >>>>> Therefore recoveries never would start. >>>>> >>>>> 2. soft commit is very low ie. 5 sec. This is a business requirement >> so >>>>> not much can be done here. >>>>> >>>>> As the standard/default admin/ping request handler is using *:* >> queries >>> , >>>>> the response time is much higher, and i am looking for an option to >>> change >>>>> the same so that the ping handler returns the results within few >>>>> miliseconds. >>>>> >>>>> here is an example for standard query time: >>>>> >>>>> ----snip--- >>>>> curl " >>>>> >>> >> http://hostname:8983/solr/parts/select?indent=on&q=*:*&rows=0&wt=json&distrib=false&debug=timing >>>>> " >>>>> { >>>>> "responseHeader":{ >>>>> "zkConnected":true, >>>>> "status":0, >>>>> "QTime":16620, >>>>> "params":{ >>>>> "q":"*:*", >>>>> "distrib":"false", >>>>> "debug":"timing", >>>>> "indent":"on", >>>>> "rows":"0", >>>>> "wt":"json"}}, >>>>> "response":{"numFound":1329638799,"start":0,"docs":[] >>>>> }, >>>>> "debug":{ >>>>> "timing":{ >>>>> "time":16620.0, >>>>> "prepare":{ >>>>> "time":0.0, >>>>> "query":{ >>>>> "time":0.0}, >>>>> "facet":{ >>>>> "time":0.0}, >>>>> "facet_module":{ >>>>> "time":0.0}, >>>>> "mlt":{ >>>>> "time":0.0}, >>>>> "highlight":{ >>>>> "time":0.0}, >>>>> "stats":{ >>>>> "time":0.0}, >>>>> "expand":{ >>>>> "time":0.0}, >>>>> "terms":{ >>>>> "time":0.0}, >>>>> "block-expensive-queries":{ >>>>> "time":0.0}, >>>>> "slow-query-logger":{ >>>>> "time":0.0}, >>>>> "debug":{ >>>>> "time":0.0}}, >>>>> "process":{ >>>>> "time":16619.0, >>>>> "query":{ >>>>> "time":16619.0}, >>>>> "facet":{ >>>>> "time":0.0}, >>>>> "facet_module":{ >>>>> "time":0.0}, >>>>> "mlt":{ >>>>> "time":0.0}, >>>>> "highlight":{ >>>>> "time":0.0}, >>>>> "stats":{ >>>>> "time":0.0}, >>>>> "expand":{ >>>>> "time":0.0}, >>>>> "terms":{ >>>>> "time":0.0}, >>>>> "block-expensive-queries":{ >>>>> "time":0.0}, >>>>> "slow-query-logger":{ >>>>> "time":0.0}, >>>>> "debug":{ >>>>> "time":0.0}}}}} >>>>> >>>>> >>>>> ----snap---- >>>>> >>>>> can we use query: _root_:abc in the ping request handler ? Tried this >>> query >>>>> and its returning the results within few miliseconds and also the >> nodes >>> are >>>>> able to recover without any issue. >>>>> >>>>> we want to use _root_ field for querying as this field is available in >>> all >>>>> our clusters with below definition: >>>>> <field name="_root_" type="string" omitNorms="true" indexed="true" >>>>> termOffsets="false" stored="false" termPayloads="false" termPositions= >>>>> "false" docValues="false" termVectors="false"/> >>>>> Could you please let me know if using _root_ for querying in >>>>> pingRequestHandler will cause any problem? >>>>> >>>>> <requestHandler name="/admin/ping" class="solr.PingRequestHandler"> >> <lst >>>>> name="invariants"> <str name="qt">/select</str><!-- handler to >> delegate >>> to >>>>> --> <str name="q">_root_:abc</str> </lst> </requestHandler> >>>>> >>>>> >>>>> -- >>>>> Best Regards, >>>>> Dinesh Naik >>> >>> >> > > > -- > Best Regards, > Dinesh Naik
