Re: [Bigdata-developers] After a timeout I get only timeouts

[Daniel H. <da...@de...>]

Brad, As you said that the thread pool size does not affect queries if I 
am running them sequentially, then I have not proved modifying it yet. 
Instead, I proved modifying the order of queries. I post the results here:

https://gist.github.com/danielhz/6066f0136ede5f50b495acb9236b8e3c

The first column is the id of the query (now I'm running only 50). 
Queries are generated parametrically and are of the form

SELECT * WHERE { P1 OPTIONAL P1 } LIMIT 10000

Where P1 and P2 are two basic graph patterns generated parametrically. 
They are not complex basic graph patterns. In fact, each of them has no 
more than 3 triples patterns. The data is huge. It includes 583 millions 
of triples.

The columns in the results are respectively the id of the query, the 
time and the result status (200 if success) or an error explanation. In 
the case of a timeout in the http client (timeout status), the time is 
elapsed time for the query in the client. In the case of a timeout in 
the server (parsing-error status), the body of the request truncated by 
a Java exception message and thus not a valid JSON document.

I the two experiments timeout there are always timeouts. Also, the query 
that produces the timeout is not necessary complex. In fact, I have run 
again only the query 48 (that produces the timeout when shuffling 
queries). I takes 0.9 seconds and gets only 9 solutions.

Note that between each experiment I restart Blazegraph, thus, I guess 
that the query was not cached in RAM. Maybe disk pages where cached by 
the system.

Thanks,
Daniel