GWicke added a comment.

>>! In T76373#799513, @Smalyshev wrote:
> Technical issues:
> 
> # On import, titan sometimes slows down and gets into GC loops. 
> # On querying, for vertices with a lot of edges (such as 
> `wd("Q5").in("P31")`, i.e. "humans", titan produces a backend exception: 
> 
> ```
> Caused by: org.apache.thrift.transport.TTransportException: Frame size 
> (17555240) larger than max length (16384000)!
> 
> ```

Possibly related: 
http://stackoverflow.com/questions/23055507/java-sql-sqlnontransientconnectionexception-org-apache-thrift-transport-ttransp

Bumping up `thrift_framed_transport_size_in_mb` might help.

Generally, the thrift interface is the old & low-level way to interact with 
Cassandra. https://github.com/thinkaurelius/titan/issues/312 discusses 
switching to native transport, but it seems that it isn't merged yet. Native 
transport has some nifty features like autopaging / streaming.

Another option that might help is 
https://github.com/thinkaurelius/titan/wiki/Using-Cassandra#titan-embedded-mode,
 as that cuts out thrift altogether by running cassandra in-process.

> Example query: 
> 
> ```
> g.wd('Q5').in('P31').labelEn[0]. 
> 
> ```
> However, `g.wd('Q5').in('P31')[0].labelEn` works.

TASK DETAIL
  https://phabricator.wikimedia.org/T76373

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To: Smalyshev, GWicke
Cc: Smalyshev, Manybubbles, GWicke, JanZerebecki, jkroll, Wikidata-bugs, aude, 
daniel



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