orsher1 Software, Support, and Training for Apache Cassandra en-US Thu, 20 Jun 2013 04:52:25 +0000 http://bbpress.org/?v=1.0.3 q http://www.datastax.com/support-forums/search.php http://www.datastax.com/support-forums/topic/empty-rows-in-the-sstables#post-8626 Thu, 24 Jan 2013 08:57:59 +0000 or.sher1 8626@http://www.datastax.com/support-forums/ <p>Hi all,</p> <p>Using sstable2json I found that some of my sstables contains empty rows such as:<br /> "key1": {"SC1": {"deletedAt": -9223372036854775808, "subColumns": []}},<br /> "key2": {},<br /> ...</p> <p>I can't understand when and why a flush operation would generate such an empty rows.<br /> If it supposed to mean that all data for that keys is deleted wouldn't I suppose to see tombstones here??<br /> Can someone give me an example of when this kind of rows can be generated?</p> <p>Thanks,<br /> Or. </p> http://www.datastax.com/support-forums/topic/cassandra-out-of-memory-issues#post-8245 Mon, 31 Dec 2012 15:29:15 +0000 or.sher1 8245@http://www.datastax.com/support-forums/ <p>Hi all,</p> <p>Our Cassandras 1.0.9 production cluster is having allot of Out-Of-Memory Crashes.<br /> The JVM heap is configured to it's highest recommended value (8GB - according to the docs).<br /> These failures occur as a response for the application server writing massive data at once and than read massive data.<br /> We're collection Column Families and other general statistics of Cassandra and the thing is that when the JVM reports that it got to the 8GB limit cfstats shows the total memory consumed by MemTables is less than 1GB.<br /> The question is, what consumes the other 7GB?<br /> What other memory structures live inside the heap?<br /> Could it be that its just a matter of Garbage Collection tuning?</p> <p>Thanks in advance,<br /> Or. </p>