Hi Joel, Regarding the implementation, I am wrapping the topmost TupleStream in a ParallelStream and execute it on the worker cluster (one of the joined cluster doubles up as worker cluster). ParallelStream does submit the query to /stream handler. for #2, for e.g. I am creating 2 CloudSolrStreams , wrapping them in IntersectStream and wrapping that in ParallelStream and reading out the tuples from parallel stream. close() is called on parallelStream. I do have custom streams but that is similar to intersectStream. I am on solr 6.3.1 The 2 solr clusters serving the join queries are having many shards. Worker collection is also multi sharded and is one from the main clusters, so do you imply I should be using a single sharded "worker" collection? Would the joins execute faster? On a side note, increasing the workers beyond 1 was not improving the execution times but was degrading if number was 3 and above. That is counter intuitive since the joins are huge and putting more workers should have improved the performance.
Thanks, Susmit On Mon, May 15, 2017 at 6:47 AM, Joel Bernstein <joels...@gmail.com> wrote: > Ok please do report any issues you run into. This is quite a good bug > report. > > I reviewed the code and I believe I see the problem. The problem seems to > be that output code from the /stream handler is not properly accounting for > client disconnects and closing the underlying stream. What I see in the > code is that exceptions coming from read() in the stream do automatically > close the underlying stream. But exceptions from the writing of the stream > do not close the stream. This needs to be fixed. > > A few questions about your streaming implementation: > > 1) Are you sending requests to the /stream handler? Or are you embedding > CloudSolrStream in your application and bypassing the /stream handler? > > 2) If you're sending Streaming Expressions to the stream handler are you > using SolrStream or CloudSolrStream to send the expression? > > 3) What version of Solr are you using. > > 4) Have you implemented any custom streams? > > > #2 is an important question. If you're sending expressions to the /stream > handler using CloudSolrStream the collection running the expression would > have to be setup a specific way. The collection running the expression will > have to be a* single shard collection*. You can have as many replicas as > you want but only one shard. That's because CloudSolrStream picks one > replica in each shard to forward the request to then merges the results > from the shards. So if you send in an expression using CloudSolrStream that > expression will be sent to each shard to be run and each shard will be > duplicating the work and return duplicate results. > > > > > > > > > > > > > > > > > > > > > Joel Bernstein > http://joelsolr.blogspot.com/ > > On Sat, May 13, 2017 at 7:03 PM, Susmit Shukla <shukla.sus...@gmail.com> > wrote: > > > Thanks Joel > > Streaming is awesome, just had a huge implementation in my project. I > found > > out a couple more issues with streaming and did local hacks for them, > would > > raise them too. > > > > On Sat, May 13, 2017 at 2:09 PM, Joel Bernstein <joels...@gmail.com> > > wrote: > > > > > Ah, then this is unexpected behavior. Can you open a ticket for this? > > > > > > Joel Bernstein > > > http://joelsolr.blogspot.com/ > > > > > > On Sat, May 13, 2017 at 2:51 PM, Susmit Shukla < > shukla.sus...@gmail.com> > > > wrote: > > > > > > > Hi Joel, > > > > > > > > I was using CloudSolrStream for the above test. Below is the call > > stack. > > > > > > > > at > > > > org.apache.http.impl.io.ChunkedInputStream.read( > > > > ChunkedInputStream.java:215) > > > > at > > > > org.apache.http.impl.io.ChunkedInputStream.close( > > > > ChunkedInputStream.java:316) > > > > at > > > > org.apache.http.impl.execchain.ResponseEntityProxy.streamClosed( > > > > ResponseEntityProxy.java:128) > > > > at > > > > org.apache.http.conn.EofSensorInputStream.checkClose( > > > > EofSensorInputStream.java:228) > > > > at > > > > org.apache.http.conn.EofSensorInputStream.close( > > > > EofSensorInputStream.java:174) > > > > at sun.nio.cs.StreamDecoder.implClose(StreamDecoder.java:378) > > > > at sun.nio.cs.StreamDecoder.close(StreamDecoder.java:193) > > > > at java.io.InputStreamReader.close(InputStreamReader.java:199) > > > > at > > > > org.apache.solr.client.solrj.io.stream.JSONTupleStream. > > > > close(JSONTupleStream.java:91) > > > > at > > > > org.apache.solr.client.solrj.io.stream.SolrStream.close( > > > > SolrStream.java:186) > > > > > > > > Thanks, > > > > Susmit > > > > > > > > On Sat, May 13, 2017 at 10:48 AM, Joel Bernstein <joels...@gmail.com > > > > > > wrote: > > > > > > > > > I was just reading the Java docs on the ChunkedInputStream. > > > > > > > > > > "Note that this class NEVER closes the underlying stream" > > > > > > > > > > In that scenario the /export would indeed continue to send data. I > > > think > > > > we > > > > > can consider this an anti-pattern for the /export handler > currently. > > > > > > > > > > I would suggest using one of the Streaming Clients to connect to > the > > > > export > > > > > handler. Either CloudSolrStream or SolrStream will both interact > with > > > the > > > > > /export handler in a the way that it expects. > > > > > > > > > > > > > > > Joel Bernstein > > > > > http://joelsolr.blogspot.com/ > > > > > > > > > > On Sat, May 13, 2017 at 12:28 PM, Susmit Shukla < > > > shukla.sus...@gmail.com > > > > > > > > > > wrote: > > > > > > > > > > > Hi Joel, > > > > > > > > > > > > I did not observe that. On calling close() on stream, it cycled > > > through > > > > > all > > > > > > the hits that /export handler calculated. > > > > > > e.g. with a *:* query and export handler on a 100k document > index, > > I > > > > > could > > > > > > see the 100kth record printed on the http wire debug log although > > > close > > > > > was > > > > > > called after reading 1st tuple. The time taken for the operation > > with > > > > > > close() call was same as that if I had read all the 100k tuples. > > > > > > As I have pointed out, close() on underlying ChunkedInputStream > > calls > > > > > > read() and solr server has probably no way to distinguish it from > > > > read() > > > > > > happening from regular tuple reads.. > > > > > > I think there should be an abort() API for solr streams that > hooks > > > into > > > > > > httpmethod.abort() . That would enable client to disconnect early > > and > > > > > > probably that would disconnect the underlying socket so there > would > > > be > > > > no > > > > > > leaks. > > > > > > > > > > > > Thanks, > > > > > > Susmit > > > > > > > > > > > > > > > > > > On Sat, May 13, 2017 at 7:42 AM, Joel Bernstein < > > joels...@gmail.com> > > > > > > wrote: > > > > > > > > > > > > > If the client closes the connection to the export handler then > > this > > > > > > > exception will occur automatically on the server. > > > > > > > > > > > > > > Joel Bernstein > > > > > > > http://joelsolr.blogspot.com/ > > > > > > > > > > > > > > On Sat, May 13, 2017 at 1:46 AM, Susmit Shukla < > > > > > shukla.sus...@gmail.com> > > > > > > > wrote: > > > > > > > > > > > > > > > Hi Joel, > > > > > > > > > > > > > > > > Thanks for the insight. How can this exception be > thrown/forced > > > > from > > > > > > > client > > > > > > > > side. Client can't do a System.exit() as it is running as a > > > webapp. > > > > > > > > > > > > > > > > Thanks, > > > > > > > > Susmit > > > > > > > > > > > > > > > > On Fri, May 12, 2017 at 4:44 PM, Joel Bernstein < > > > > joels...@gmail.com> > > > > > > > > wrote: > > > > > > > > > > > > > > > > > In this scenario the /export handler continues to export > > > results > > > > > > until > > > > > > > it > > > > > > > > > encounters a "Broken Pipe" exception. This exception is > > trapped > > > > and > > > > > > > > ignored > > > > > > > > > rather then logged as it's not considered an exception if > the > > > > > client > > > > > > > > > disconnects early. > > > > > > > > > > > > > > > > > > Joel Bernstein > > > > > > > > > http://joelsolr.blogspot.com/ > > > > > > > > > > > > > > > > > > On Fri, May 12, 2017 at 2:10 PM, Susmit Shukla < > > > > > > > shukla.sus...@gmail.com> > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > Hi, > > > > > > > > > > > > > > > > > > > > I have a question regarding solr /export handler. Here is > > the > > > > > > > scenario > > > > > > > > - > > > > > > > > > > I want to use the /export handler - I only need sorted > data > > > and > > > > > > this > > > > > > > is > > > > > > > > > the > > > > > > > > > > fastest way to get it. I am doing multiple level joins > > using > > > > > > streams > > > > > > > > > using > > > > > > > > > > /export handler. I know the number of top level records > to > > be > > > > > > > retrieved > > > > > > > > > but > > > > > > > > > > not for each individual stream rolling up to the final > > > result. > > > > > > > > > > I observed that calling close() on a /export stream is > too > > > > > > expensive. > > > > > > > > It > > > > > > > > > > reads the stream to the very end of hits. Assuming there > > are > > > > 100 > > > > > > > > million > > > > > > > > > > hits for each stream ,first 1k records were found after > > joins > > > > and > > > > > > we > > > > > > > > call > > > > > > > > > > close() after that, it would take many minutes/hours to > > > finish > > > > > it. > > > > > > > > > > Currently I have put close() call in a different thread - > > > > > basically > > > > > > > > fire > > > > > > > > > > and forget. But the cluster is very strained because of > the > > > > > > > > unneccessary > > > > > > > > > > reads. > > > > > > > > > > > > > > > > > > > > Internally streaming uses ChunkedInputStream of > HttpClient > > > and > > > > it > > > > > > has > > > > > > > > to > > > > > > > > > be > > > > > > > > > > drained in the close() call. But from server point of > view, > > > it > > > > > > should > > > > > > > > > stop > > > > > > > > > > sending more data once close() has been issued. > > > > > > > > > > There is a read() call in close() method of > > > ChunkedInputStream > > > > > that > > > > > > > is > > > > > > > > > > indistinguishable from real read(). If /export handler > > stops > > > > > > sending > > > > > > > > more > > > > > > > > > > data after close it would be very useful. > > > > > > > > > > > > > > > > > > > > Another option would be to use /select handler and get > into > > > > > > business > > > > > > > of > > > > > > > > > > managing a custom cursor mark that is based on the stream > > > sort > > > > > and > > > > > > is > > > > > > > > > reset > > > > > > > > > > until it fetches the required records at topmost level. > > > > > > > > > > > > > > > > > > > > Any thoughts. > > > > > > > > > > > > > > > > > > > > Thanks, > > > > > > > > > > Susmit > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
