Re: sync commitlog in batch mode lose data

But I have another question, while I disable the disk cache but leave the cache write mode write-back, how sync works ? Still write the data into the cache ? This issue may not belong to the scope of discussion here  . I'm not sure, it depends on at what level of abstraction you changed to

Re: sync commitlog in batch mode lose data

I disable the disk cache of RAID controller,  unfortunately it still lost some data. Disabling caching shouldn't be necessary so much as ensuring that all layers honor write barriers properly. A battery backed cache that survives a power outtage need not be disabled (and usually if you have

Re: sync commitlog in batch mode lose data

Thank you very much Peter ! After I disable the disk cache and change the cache write mode from write-back to write-through, I saw the result I'd like to see. It seems fsync() only synced the data to the disk cache but not the storage devices while disk cache sync mode in write-back. But I have

Re: sync commitlog in batch mode lose data

Your Losing data because at level quorm with 2 nodes becomes all. Cassandra will not even try to write data after the node goes down . Client should see unavailableexception. For a small window after the failure you will see timedoutexception and those writes should hit the commitlog. On

Re: sync commitlog in batch mode lose data

I disable the disk cache of RAID controller, unfortunately it still lost some data. 2011/6/1 Peter Schuller peter.schul...@infidyne.com 1). set commitlog sync in batch mode and the sync batch window in 0 ms 2). one client wrote random keys in infinite loop with consistency level QUORUM

Re: sync commitlog in batch mode lose data

wait geili reply 2011/6/1 Preston Chang zhangyf2...@gmail.com I disable the disk cache of RAID controller, unfortunately it still lost some data. 2011/6/1 Peter Schuller peter.schul...@infidyne.com 1). set commitlog sync in batch mode and the sync batch window in 0 ms 2). one client

sync commitlog in batch mode lose data

Hi, I have a cluster with two nodes (node A and node B) and make a test as follows: 1). set commitlog sync in batch mode and the sync batch window in 0 ms 2). one client wrote random keys in infinite loop with consistency level QUORUM and record the keys in file after the insert() method return

Re: sync commitlog in batch mode lose data

How much replication factor did you set for the keyspace? If the RF is 2, your data should be replicated to both of nodes. If the RF is 1, you will lose the half of data when the node A is down. maki 2011/5/31 Preston Chang zhangyf2...@gmail.com: Hi, I have a cluster with two nodes (node A

Re: sync commitlog in batch mode lose data

My RF is 2. When the node A is down, the commit log should be fsynced to disk in my test scene, so there should be no NOTFOUND key, but there are some NOTFOUND keys. I am puzzled. 2011/5/31 Maki Watanabe watanabe.m...@gmail.com How much replication factor did you set for the keyspace? If the

Re: sync commitlog in batch mode lose data

In your step 5 which node are you connected to ? There is a possibility that during the time node A was turning off, mutations which had been started were completed on node B. In which case the client would have gotten a TimedOutExceptions. Meaning the operation did not complete at the

Re: sync commitlog in batch mode lose data

1). set commitlog sync in batch mode and the sync batch window in 0 ms 2). one client wrote random keys in infinite loop with consistency level QUORUM and record the keys in file after the insert() method return normally 3). unplug one server (node A) power cord 4). restart the server and