Hi There

 

I just came across a situation where a unified highlighting search under
solr 8.8.0/8.8.1 can take over 20 mins to run and eventually times out. I
resolved it by a config change - but it can catch you out. Hence this email.

 

With solr 8.8.0 a new unified highlighting parameter &hl.fragAlignRatio was
implemented which if not set defaults to 0.5. This attempts to improve the
high lighting so that highlighted text does not appear right at the left.
This works well but if you have a search result with numerous occurrences of
the word in question within the record performance goes right down!

 

2021-02-27 06:45:03.151 INFO  (qtp762476028-20) [   x:uleaf]
o.a.s.c.S.Request [uleaf]  webapp=/solr path=/select
params={hl.snippets=2&q=test&hl=on&hl.maxAnalyzedChars=1000000&fl=id,descrip
tion,specification,score&start=20&hl.fl=*&rows=10&_=1614405119134}
hits=57008 status=0 QTime=1414320

2021-02-27 06:45:03.245 INFO  (qtp762476028-20) [   x:uleaf]
o.a.s.s.HttpSolrCall Unable to write response, client closed connection or
we are shutting down => org.eclipse.jetty.io.EofException

              at
org.eclipse.jetty.io.ChannelEndPoint.flush(ChannelEndPoint.java:279)

org.eclipse.jetty.io.EofException: null

              at
org.eclipse.jetty.io.ChannelEndPoint.flush(ChannelEndPoint.java:279)
~[jetty-io-9.4.34.v20201102.jar:9.4.34.v20201102]

              at
org.eclipse.jetty.io.WriteFlusher.flush(WriteFlusher.java:422)
~[jetty-io-9.4.34.v20201102.jar:9.4.34.v20201102]

              at
org.eclipse.jetty.io.WriteFlusher.completeWrite(WriteFlusher.java:378)
~[jetty-io-9.4.34.v20201102.jar:9.4.34.v20201102]

 

when I set &hl.fragAlignRatio=0.25 results came back much quicker

 

2021-02-27 14:59:57.189 INFO  (qtp1291367132-24) [   x:holmes]
o.a.s.c.S.Request [holmes]  webapp=/solr path=/select
params={hl.weightMatches=false&hl=on&fl=id,description,specification,score&s
tart=1&hl.fragAlignRatio=0.25&rows=100&hl.snippets=2&q=test&hl.maxAnalyzedCh
ars=1000000&hl.fl=*&hl.method=unified&timeAllowed=90000&_=1614430061690}
hits=136939 status=0 QTime=87024

 

And  &hl.fragAlignRatio=0.1

 

2021-02-27 15:18:45.542 INFO  (qtp1291367132-19) [   x:holmes]
o.a.s.c.S.Request [holmes]  webapp=/solr path=/select
params={hl.weightMatches=false&hl=on&fl=id,description,specification,score&s
tart=1&hl.fragAlignRatio=0.1&rows=100&hl.snippets=2&q=test&hl.maxAnalyzedCha
rs=1000000&hl.fl=*&hl.method=unified&timeAllowed=90000&_=1614430061690}
hits=136939 status=0 QTime=69033

 

And &hl.fragAlignRatio=0.0

 

2021-02-27 15:20:38.194 INFO  (qtp1291367132-24) [   x:holmes]
o.a.s.c.S.Request [holmes]  webapp=/solr path=/select
params={hl.weightMatches=false&hl=on&fl=id,description,specification,score&s
tart=1&hl.fragAlignRatio=0.0&rows=100&hl.snippets=2&q=test&hl.maxAnalyzedCha
rs=1000000&hl.fl=*&hl.method=unified&timeAllowed=90000&_=1614430061690}
hits=136939 status=0 QTime=2841

 

I left our setting at 0.0 - this presumably how it was in 7.7.1 (fully left
aligned).  I am not too sure as to how many time a word has to occur in a
record for performance to go right down - but if too many it can have a BIG
impact.

 

I also noticed that setting &timeAllowed=90000 did not break out of the
query until it finished. Perhaps because the query finished quickly and what
took the time was the highlighting. It might be an idea to get &timeAllowed
to also cover any highlighting so that the query does not run until the
jetty timeout is hit. The machine 100% one core for about 20 mins!.

 

Hope this helps.

 

Regards

 

Matthew

 

Matthew Flowerday | Consultant | ULEAF

Unisys | 01908 774830|  <mailto:matthew.flower...@unisys.com>
matthew.flower...@unisys.com 

Address Enigma | Wavendon Business Park | Wavendon | Milton Keynes | MK17
8LX

 

 <http://www.unisys.com/> 

 

THIS COMMUNICATION MAY CONTAIN CONFIDENTIAL AND/OR OTHERWISE PROPRIETARY
MATERIAL and is for use only by the intended recipient. If you received this
in error, please contact the sender and delete the e-mail and its
attachments from all devices.

 <http://www.linkedin.com/company/unisys>    <http://twitter.com/unisyscorp>
<http://www.youtube.com/theunisyschannel>
<http://www.facebook.com/unisyscorp>  <https://vimeo.com/unisys>
<http://blogs.unisys.com/> 

 

Attachment: smime.p7s
Description: S/MIME cryptographic signature

Reply via email to