I think I had (and have) a similar problem:
Hm - had to digg deeper and it totally looks like a native mem leak to me:We are still growing with res += 100MB a day. Cassandra is > 8G nowI checked the cassandra process with pmap -xHere's the human readable (aggregated) output:Format is thingy: RSS in KBSummary:
Total SST: 1961616Anon RSS: 6499640Total RSS: 8478376Here's a little more detail:SSTables (data and index files)******Attic: 0PrivateChatNotification: 38108Schema: 0PrivateChat: 161048UserData: 116788HintsColumnFamily: 0Rooms: 100548Tracker: 476Migrations: 0ObjectRepository: 793680BlobStore: 350924Activities: 400044LocationInfo: 0Libraries******javajar: 2292nativelib: 13028Other******28201: 32jna979649866618987247.tmp: 92locale-archive: 1492[stack]: 132java: 44ffi8TsQPY(deleted): 8And******[anon]: 6499640Maybe the output of pmap is totally misleading but my interpretation is that only 2GB of RSS is attributed to paged in sstables.I have one large anon block which looks like this:Address Kbytes RSS Dirty Mode Mapping000000073f600000 0 3093248 3093248 rwx-- [ anon ]This is the native heap thats been allocated on startup and mlockedSo theres still 3.5GB of anon memory.We haven't deployed https://issues.apache.org/jira/browse/CASSANDRA-2654 yet and this might be part of it but I don't think thats the main problem.As I said mem goes up by 100MB each day pretty linearly.Would be great if anyone could verify this by running pmap or talk my off the roof by explaining that nothing's the way it seems.All this might be heavily OS specific so maybe that's only on Debian?Thanks a lotDanielOn Jul 4, 2011, at 2:42 PM, Jonathan Ellis wrote:mmap'd data will be attributed to res, but the OS can page it out
instead of killing the process.
On Mon, Jul 4, 2011 at 5:52 AM, Daniel Doubleday
<email@example.com> wrote:Hi all,we have a mem problem with cassandra. res goes up without bounds (well untilthe os kills the process because we dont have swap)I found a thread that's about the same problem but on OpenJDK:
We are on Debian with Sun JDK.Resident mem is 7.4G while heap is restricted to 3G.Anyone else is seeing this with Sun JDK?
Cheers,Daniel:/home/dd# java -versionjava version "1.6.0_24"
Java(TM) SE Runtime Environment (build 1.6.0_24-b07)Java HotSpot(TM) 64-Bit Server VM (build 19.1-b02, mixed mode):/home/dd# ps aux |grep javacass 28201 9.5 46.8 372659544 7707172 ? SLl May24 5656:21/usr/bin/java -ea -XX:+UseThreadPriorities -XX:ThreadPriorityPolicy=42
-Xms3000M -Xmx3000M -Xmn400M ...PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
28201 cass 20 0 355g 7.4g 1.4g S 8 46.9 5656:25 java
Project Chair, Apache Cassandra
co-founder of DataStax, the source for professional Cassandra support