On 14 October 2015 at 20:35, Pushkar Raste <pushkar.raste@gmail.com> wrote:
> You may want to start solr with following settings to enable logging GC
> details. Here are some flags you might want to enable.
>
> Xloggc:<path_to_log_dir>/gc.log
> XX:+PrintGCDetails
> XX:+PrintGCDateStamps
> XX:+PrintGCTimeStamps
> XX:+PrintTenuringDistribution
> XX:+PrintGCApplicationStoppedTime
> XX:+PrintHeapAtGC
>
> Once you have GC logs, look for string "Total time for which application
> threads were stopped" to check if you have long pauses (you may get long
> pauses even with young generation GC).
>
Yes, there are several lines indicating that threads are being stopped.
There is this one particularly that draw my attention because right after a
second it happened 2 of my replicas went into
recovery mode, including the one who suffered the thread stop.
solr_gc.log.1.current:20151015T07:47:03.263+0000: 251173.653: Total time
for which application threads were stopped: 1.4936161 seconds, Stopping
threads took: 0.0000502 seconds
(is a second of stopped threads enough to have a node in recovery node ?)
When this happened, the leader had a couple of connection resets while
trying to communicate with this replica.
and this server the highest stop takes 4s.
solr_gc.log.1.current:20151014T20:24:01.353+0000: 210191.743: Total time
for which application threads were stopped: 4.0111066 seconds, Stopping
threads took: 0.0000776 seconds
These are the jvm flags
XX:NewSize=256m XX:MaxNewSize=256m
/usr/lib/jvm/java8oracle/bin/java server Xss256k Xms16g Xmx16g
XX:NewRatio=3 XX:SurvivorRatio=4 XX:TargetSurvivorRatio=90
XX:MaxTenuringThreshold=8 XX:+UseConcMarkSweepGC XX:+UseParNewGC
XX:ConcGCThreads=4 XX:ParallelGCThreads=4 XX:+CMSScavengeBeforeRemark
XX:PretenureSizeThreshold=64m XX:+UseCMSInitiatingOccupancyOnly
XX:CMSInitiatingOccupancyFraction=50 XX:CMSMaxAbortablePrecleanTime=6000
XX:+CMSParallelRemarkEnabled XX:+ParallelRefProcEnabled verbose:gc
XX:+PrintHeapAtGC XX:+PrintGCDetails XX:+PrintGCDateStamps
XX:+PrintGCTimeStamps XX:+PrintTenuringDistribution
XX:+PrintGCApplicationStoppedTime Xloggc:/solr_gc.log
DzkClientTimeout=15000 Duser.timezone=UTC
Djava.net.preferIPv4Stack=true DzkClientTimeout=30000 XX:NewSize=256m
XX:MaxNewSize=256m
All of the options are the default that come with the solr startup script,
only the ones specified in the first line are being put by us.
>
>  Pushkar Raste
>
> On Wed, Oct 14, 2015 at 11:47 AM, Lorenzo Fundaró <
> lorenzo.fundaro@dawandamail.com> wrote:
>
> > <<What do you see if you attach
> > &debug=true to the query?>>
> >
> > "debug": { "rawquerystring": "*:*", "querystring": "*:*", "parsedquery":
> > "(+MatchAllDocsQuery(*:*))/no_coord", "parsedquery_toString": "+*:*", "
> > explain": { "Product:47047358": "\n1.0 = (MATCH) MatchAllDocsQuery,
> product
> > of:\n 1.0 = queryNorm\n", "Product:32211113": "\n1.0 = (MATCH)
> > MatchAllDocsQuery, product of:\n 1.0 = queryNorm\n", "Product:30852121":
> > "\n1.0
> > = (MATCH) MatchAllDocsQuery, product of:\n 1.0 = queryNorm\n", "
> > Product:35018929": "\n1.0 = (MATCH) MatchAllDocsQuery, product of:\n 1.0
> =
> > queryNorm\n", "Product:31682082": "\n1.0 = (MATCH) MatchAllDocsQuery,
> > product of:\n 1.0 = queryNorm\n", "Product:31077677": "\n1.0 = (MATCH)
> > MatchAllDocsQuery, product of:\n 1.0 = queryNorm\n", "Product:22298365":
> > "\n1.0
> > = (MATCH) MatchAllDocsQuery, product of:\n 1.0 = queryNorm\n", "
> > Product:41094514": "\n1.0 = (MATCH) MatchAllDocsQuery, product of:\n 1.0
> =
> > queryNorm\n", "Product:13106166": "\n1.0 = (MATCH) MatchAllDocsQuery,
> > product of:\n 1.0 = queryNorm\n", "Product:19142249": "\n1.0 = (MATCH)
> > MatchAllDocsQuery, product of:\n 1.0 = queryNorm\n", "Product:38243373":
> > "\n1.0
> > = (MATCH) MatchAllDocsQuery, product of:\n 1.0 = queryNorm\n", "
> > Product:20434065": "\n1.0 = (MATCH) MatchAllDocsQuery, product of:\n 1.0
> =
> > queryNorm\n", "Product:25194801": "\n1.0 = (MATCH) MatchAllDocsQuery,
> > product of:\n 1.0 = queryNorm\n", "Product:885482": "\n1.0 = (MATCH)
> > MatchAllDocsQuery, product of:\n 1.0 = queryNorm\n", "Product:45356790":
> > "\n1.0
> > = (MATCH) MatchAllDocsQuery, product of:\n 1.0 = queryNorm\n", "
> > Product:67719831": "\n1.0 = (MATCH) MatchAllDocsQuery, product of:\n 1.0
> =
> > queryNorm\n", "Product:12843394": "\n1.0 = (MATCH) MatchAllDocsQuery,
> > product of:\n 1.0 = queryNorm\n", "Product:38126213": "\n1.0 = (MATCH)
> > MatchAllDocsQuery, product of:\n 1.0 = queryNorm\n", "Product:38798130":
> > "\n1.0
> > = (MATCH) MatchAllDocsQuery, product of:\n 1.0 = queryNorm\n", "
> > Product:30292169": "\n1.0 = (MATCH) MatchAllDocsQuery, product of:\n 1.0
> =
> > queryNorm\n", "Product:11535854": "\n1.0 = (MATCH) MatchAllDocsQuery,
> > product of:\n 1.0 = queryNorm\n", "Product:8443674": "\n1.0 = (MATCH)
> > MatchAllDocsQuery, product of:\n 1.0 = queryNorm\n", "Product:51012182":
> > "\n1.0
> > = (MATCH) MatchAllDocsQuery, product of:\n 1.0 = queryNorm\n", "
> > Product:75780871": "\n1.0 = (MATCH) MatchAllDocsQuery, product of:\n 1.0
> =
> > queryNorm\n", "Product:20227881": "\n1.0 = (MATCH) MatchAllDocsQuery,
> > product of:\n 1.0 = queryNorm\n", "Product:38093629": "\n1.0 = (MATCH)
> > MatchAllDocsQuery, product of:\n 1.0 = queryNorm\n", "Product:3142218":
> > "\n1.0
> > = (MATCH) MatchAllDocsQuery, product of:\n 1.0 = queryNorm\n", "
> > Product:15295602": "\n1.0 = (MATCH) MatchAllDocsQuery, product of:\n 1.0
> =
> > queryNorm\n", "Product:3375982": "\n1.0 = (MATCH) MatchAllDocsQuery,
> > product of:\n 1.0 = queryNorm\n", "Product:38276777": "\n1.0 = (MATCH)
> > MatchAllDocsQuery, product of:\n 1.0 = queryNorm\n", "Product:10726118":
> > "\n1.0
> > = (MATCH) MatchAllDocsQuery, product of:\n 1.0 = queryNorm\n", "
> > Product:50827742": "\n1.0 = (MATCH) MatchAllDocsQuery, product of:\n 1.0
> =
> > queryNorm\n", "Product:5771722": "\n1.0 = (MATCH) MatchAllDocsQuery,
> > product of:\n 1.0 = queryNorm\n", "Product:3245678": "\n1.0 = (MATCH)
> > MatchAllDocsQuery, product of:\n 1.0 = queryNorm\n", "Product:13702130":
> > "\n1.0
> > = (MATCH) MatchAllDocsQuery, product of:\n 1.0 = queryNorm\n", "
> > Product:25679953": "\n1.0 = (MATCH) MatchAllDocsQuery, product of:\n 1.0
> =
> > queryNorm\n" }, "QParser": "ExtendedDismaxQParser", "altquerystring":
> null,
> > "boost_queries": null, "parsed_boost_queries": [], "boostfuncs": null, "
> > filter_queries": [ "{!cost=1 cache=true}type_s:Product AND
> > is_valid_b:true",
> > "{!cost=50 cache=true}in_languages_t:de", "{!cost=99
> > cache=false}(shipping_country_codes_mt: (DE OR EURO OR EUR OR ALL)) AND
> > (cents_ri: [* TO 3000])" ], "parsed_filter_queries": [ "+type_s:Product
> > +is_valid_b:true", "in_languages_t:de", "{!cache=false
> > cost=99}+(shipping_country_codes_mt:de shipping_country_codes_mt:euro
> > shipping_country_codes_mt:eur shipping_country_codes_mt:all) +cents_ri:[*
> > TO 3000]" ], "timing": { "time": 18, "prepare": { "time": 0, "query": { "
> > time": 0 }, "facet": { "time": 0 }, "mlt": { "time": 0 }, "highlight": {
> "
> > time": 0 }, "stats": { "time": 0 }, "expand": { "time": 0 },
> "spellcheck":
> > {
> > "time": 0 }, "debug": { "time": 0 } }, "process": { "time": 18, "query":
> {
> > "
> > time": 0 }, "facet": { "time": 0 }, "mlt": { "time": 0 }, "highlight": {
> "
> > time": 0 }, "stats": { "time": 0 }, "expand": { "time": 0 },
> "spellcheck":
> > {
> > "time": 0 }, "debug": { "time": 18 } }
> >
> > I think this clause is wrong:
> > (cents_ri: [* 3000])
> >
> > I think you mean
> > (cents_ri: [* TO 3000])
> >
> > I think I made no difference. I tried both and they both worked.
> >
> > But are these slow queries constant or intermittent?
> >
> > They are definetly cached. The second time runs in no time.
> >
> > I gonna try adding them in the pre warmcache too. And see the results.
> >
> > The field that I used for sorting is indexed but not stored and it's not
> a
> > DocValue. I tried the query without the sort and the performance didnt
> > change significantly.
> >
> > By the time I saw that log, the server was getting around 7k updates per
> > minute. The query information I don't have it now, but I think it will
> > qualify as heavy load query.
> >
> > Thank you !
> >
> >
> > On 14 October 2015 at 17:14, Erick Erickson <erickerickson@gmail.com>
> > wrote:
> >
> > > A couple of things don't particularly make sense here:
> > >
> > > You specify edismax, q=*:* yet you specify qf=
> > > You're searching across whatever you defined as the default
> > > field in the request handler. What do you see if you attach
> > > &debug=true to the query?
> > >
> > > I think this clause is wrong:
> > > (cents_ri: [* 3000])
> > >
> > > I think you mean
> > > (cents_ri: [* TO 3000])
> > >
> > > I'm not sure either of those is the problem, but are places I'd start.
> > >
> > > As far as the size of your filter cache goes, a hit ratio of .87
> actually
> > > isn't bad. Upping the size would add some marginal benefit, but it's
> > > unlikely to be a magic bullet.
> > >
> > > But are these slow queries constant or intermittent? In other words,
> > > are all queries of this general form slow or just the first few? In
> > > particular
> > > is the first query that mentions sorting on this field slow but
> > subsequent
> > > ones faster? In that case consider adding a query to the newSearcher
> > > event in solrconfig.xml that mentions this sort, that would prewarm
> > > the sort values. Also, defining all fields that you sort on as
> > > docValues="true"
> > > is recommended at this point.
> > >
> > > What I'd try is removing clauses to see which one is the problem. On
> > > the surface this is surprisingly slow. And how heavily loaded is the
> > > server?
> > > Your autocommit settings look fine, my question is more how much
> indexing
> > > and querying is going on when you take these measurements.
> > >
> > > Best,
> > > Erick
> > >
> > > On Wed, Oct 14, 2015 at 3:03 AM, Lorenzo Fundaró
> > > <lorenzo.fundaro@dawandamail.com> wrote:
> > > > Hello,
> > > >
> > > > I have following conf for filters and commits :
> > > >
> > > > Concurrent LFU Cache(maxSize=64, initialSize=64, minSize=57,
> > > > acceptableSize=60, cleanupThread=false, timeDecay=true,
> > autowarmCount=8,
> > > > regenerator=org.apache.solr.search.SolrIndexSearcher$2@169ee0fd)
> > > >
> > > > <autoCommit>
> > > > <! Every 15 seconds >
> > > > <maxTime>${solr.autoCommit.maxTime:15000}</maxTime>
> > > > <openSearcher>false</openSearcher>
> > > > </autoCommit>
> > > >
> > > > <autoSoftCommit>
> > > > <! Every 10 minutes >
> > > > <maxTime>${solr.autoSoftCommit.maxTime:600000}</maxTime>
> > > > </autoSoftCommit>
> > > >
> > > > and the following stats for filters:
> > > >
> > > > lookups = 3602
> > > > hits = 3148
> > > > hit ratio = 0.87
> > > > inserts = 455
> > > > evictions = 400
> > > > size = 63
> > > > warmupTime = 770
> > > >
> > > > *Problem: *a lot of slow queries, for example:
> > > >
> > > > {q=*:*&tie=1.0&defType=edismax&qt=standard&json.nl
> > > =map&qf=&fl=pk_i,score&start=0&sort=view_counter_i
> > > > desc&fq={!cost=1 cache=true}type_s:Product AND
> > > is_valid_b:true&fq={!cost=50
> > > > cache=true}in_languages_t:de&fq={!cost=99
> > > > cache=false}(shipping_country_codes_mt: (DE OR EURO OR EUR OR ALL))
> AND
> > > > (cents_ri: [* 3000])&rows=36&wt=json} hits=3768003 status=0
> QTime=1378
> > > >
> > > > I could increase the size of the filter so I would decrease the
> amount
> > of
> > > > evictions, but it seems to me this would not be solving the root
> > problem.
> > > >
> > > > Some ideas on where/how to start for optimisation ? Is it actually
> > normal
> > > > that this query takes this time ?
> > > >
> > > > We have an index of ~14 million docs. 4 replicas with two cores and 1
> > > shard
> > > > each.
> > > >
> > > > thank you.
> > > >
> > > >
> > > > 
> > > >
> > > > 
> > > > Lorenzo Fundaro
> > > > Backend Engineer
> > > > EMail: lorenzo.fundaro@dawandamail.com
> > > >
> > > > Fax + 49  (0)30  25 76 08 52
> > > > Tel + 49  (0)179  51 10 982
> > > >
> > > > DaWanda GmbH
> > > > Windscheidstraße 18
> > > > 10627 Berlin
> > > >
> > > > Geschäftsführer: Claudia Helming, Michael Pütz
> > > > Amtsgericht Charlottenburg HRB 104695 B
> > >
> >
> >
> >
> > 
> >
> > 
> > Lorenzo Fundaro
> > Backend Engineer
> > EMail: lorenzo.fundaro@dawandamail.com
> >
> > Fax + 49  (0)30  25 76 08 52
> > Tel + 49  (0)179  51 10 982
> >
> > DaWanda GmbH
> > Windscheidstraße 18
> > 10627 Berlin
> >
> > Geschäftsführer: Claudia Helming, Michael Pütz
> > Amtsgericht Charlottenburg HRB 104695 B
> >
>


Lorenzo Fundaro
Backend Engineer
EMail: lorenzo.fundaro@dawandamail.com
Fax + 49  (0)30  25 76 08 52
Tel + 49  (0)179  51 10 982
DaWanda GmbH
Windscheidstraße 18
10627 Berlin
Geschäftsführer: Claudia Helming, Michael Pütz
Amtsgericht Charlottenburg HRB 104695 B
