ignite-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From vkulichenko <valentin.kuliche...@gmail.com>
Subject Re: Failed to run reduce query locally
Date Tue, 02 Aug 2016 21:03:50 GMT
Hi David,

When you call getAll(), you fetch the whole result set to the client. If
you're doing 'select *' from a disctributed without any conditions, you will
very likely get an out of memory, because to execute such a query your
client needs to have capacity equal to the total capacity of all servers.

First of all, I would recommend to avoid such queries. You should always try
to minimize network traffic and sending the whole cache to the client is
obviously a bad idea from this standpoint.

Second of all, if the result set is still large, you'd better iterate
through the QueryCursor instead of calling getAll(). If you iterate, Ignite
will fetch data in pages, discarding old ones. So the client will have only
one page at a time in memory and will not fail.


View this message in context: http://apache-ignite-users.70518.x6.nabble.com/Failed-to-run-reduce-query-locally-tp6667p6678.html
Sent from the Apache Ignite Users mailing list archive at Nabble.com.

View raw message