Both total system memory and heap size can't be 8GB? The timeout on the Astyanax client should be greater than the timeouts on the C* nodes, otherwise your client will timeout prematurely.
Also, have you tried increasing the timeout for the range queries to a higher number? It is not recommended to set them very high, because a lot of other problems may start happening, but then reading 800,000 partitions is not a normal operation. Just as an experimentation, can you set the range timeout to 45 seconds on each node and the timeout on the Astyanax client to 50 seconds? Restart the nodes after increasing the timeout and try again. Mohammed From: Ravi Agrawal [mailto:ragra...@clearpoolgroup.com] Sent: Friday, January 16, 2015 5:11 PM To: user@cassandra.apache.org Subject: RE: Retrieving all row keys of a CF 1) What is the heap size and total memory on each node? 8GB, 8GB 2) How big is the cluster? 4 3) What are the read and range timeouts (in cassandra.yaml) on the C* nodes? 10 secs, 10 secs 4) What are the timeouts for the Astyanax client? 2 secs 5) Do you see GC pressure on the C* nodes? How long does GC for new gen and old gen take? occurs every 5 secs dont see huge gc pressure, <50ms 6) Does any node crash with OOM error when you try AllRowsReader? No From: Mohammed Guller [mailto:moham...@glassbeam.com] Sent: Friday, January 16, 2015 7:30 PM To: user@cassandra.apache.org<mailto:user@cassandra.apache.org> Subject: RE: Retrieving all row keys of a CF A few questions: 1) What is the heap size and total memory on each node? 2) How big is the cluster? 3) What are the read and range timeouts (in cassandra.yaml) on the C* nodes? 4) What are the timeouts for the Astyanax client? 5) Do you see GC pressure on the C* nodes? How long does GC for new gen and old gen take? 6) Does any node crash with OOM error when you try AllRowsReader? Mohammed From: Ravi Agrawal [mailto:ragra...@clearpoolgroup.com] Sent: Friday, January 16, 2015 4:14 PM To: user@cassandra.apache.org<mailto:user@cassandra.apache.org> Subject: Re: Retrieving all row keys of a CF Hi, I and Ruchir tried query using AllRowsReader recipe but had no luck. We are seeing PoolTimeoutException. SEVERE: [Thread_1] Error reading RowKeys com.netflix.astyanax.connectionpool.exceptions.PoolTimeoutException: PoolTimeoutException: [host=servername, latency=2003(2003), attempts=4]Timed out waiting for connection at com.netflix.astyanax.connectionpool.impl.SimpleHostConnectionPool.waitForConnection(SimpleHostConnectionPool.java:231) at com.netflix.astyanax.connectionpool.impl.SimpleHostConnectionPool.borrowConnection(SimpleHostConnectionPool.java:198) at com.netflix.astyanax.connectionpool.impl.RoundRobinExecuteWithFailover.borrowConnection(RoundRobinExecuteWithFailover.java:84) at com.netflix.astyanax.connectionpool.impl.AbstractExecuteWithFailoverImpl.tryOperation(AbstractExecuteWithFailoverImpl.java:117) at com.netflix.astyanax.connectionpool.impl.AbstractHostPartitionConnectionPool.executeWithFailover(AbstractHostPartitionConnectionPool.java:338) at com.netflix.astyanax.thrift.ThriftColumnFamilyQueryImpl$2.execute(ThriftColumnFamilyQueryImpl.java:397) at com.netflix.astyanax.recipes.reader.AllRowsReader$1.call(AllRowsReader.java:447) at com.netflix.astyanax.recipes.reader.AllRowsReader$1.call(AllRowsReader.java:419) at java.util.concurrent.FutureTask.run(FutureTask.java:262) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:745) We did receive a portion of data which changes on every try. We used following method. boolean result = new AllRowsReader.Builder<String, String>(keyspace, CF_STANDARD1) .withColumnRange(null, null, false, 0) .withPartitioner(null) // this will use keyspace's partitioner .forEachRow(new Function<Row<String, String>, Boolean>() { @Override public Boolean apply(@Nullable Row<String, String> row) { // Process the row here ... return true; } }) .build() .call(); Tried setting concurrency level as mentioned in this post (https://github.com/Netflix/astyanax/issues/411) as well on both astyanax 1.56.49 and 2.0.0. Still nothing.