Zookeeper on windows in production environment

[vishal kher]

Hi,

The Zookeeper admin guide mentions that Win32 is not supported in production 
environment. We are planning to use zookeeper on Windows production environment 
if it is stable enough. Can folks who are using Zookeeper on Win32 please share 
their experiences? How long have you been running Zookeeper on windows? Are you 
facing any stability issues? Any issues that we should be aware off? Is it 
advisable to use Zookeeper on Windows? Thanks.

Regards,
-Vishal

Re: Understanding ZooKeeper data file management and LogFormatter

[Vishal Kher]

Hi Mahadev,

I had submitted some small fixes to PurgeTxnLog in
*ZOOKEEPER-872https://issues.apache.org/jira/browse/ZOOKEEPER-872
*. Can you or someone else take a look at it?

Thanks.
-Vishal



On Mon, Sep 13, 2010 at 5:39 PM, Mahadev Konar maha...@yahoo-inc.comwrote:

 Hi Vishal,
  Usually the default retention policy is safe enough for operations.

 http://hadoop.apache.org/zookeeper/docs/r3.1.1/zookeeperAdmin.html

 Gives you an overview of how to use the purging library in zookeeper.

 Thanks
 mahadev


 On 9/8/10 12:01 PM, Vishal K vishalm...@gmail.com wrote:

  Hi All,
 
  Can you please share your experience regarding ZK snapshot retention and
  recovery policies?
 
  We have an application where we never need to rollback (i.e., revert back
 to
  a previous state by using old snapshots). Given this, I am trying to
  understand under what circumstances would we ever need to use old ZK
  snapshots. I understand a lot of these decisions depend on the
 application
  and amount of redundancy used at every level (e.g,. RAID level where the
  snapshots are stored etc) in the product. To simplify the discussion, I
  would like to rule out any application characteristics and focus mainly
 on
  data consistency.
 
  - Assuming that we have a 3 node cluster I am trying to figure out when
  would I really need to use old snapshot files. With 3 nodes we already
 have
  at least 2 servers with consistent database. If I loose files on one of
 the
  servers, I can use files from the other. In fact, ZK server join will
 take
  care of this. I can remove files from a faulty node and reboot that node.
  The faulty node will sync with the leader.
 
  - The old files will be useful if the current snapshot and/or log files
 are
  lost or corrupted on all 3 servers. If  the loss is due to a disaster
 (case
  where we loose all 3 servers), one would have to keep the snapshots on
 some
  external storage to recover. However, if the current snapshot file is
  corrupted on all 3 servers, then the most likely cause would be a bug in
 ZK.
  In which case, how can I trust the consistency of the old snapshots?
 
  - Given a set of snapshots and log files, how can I verify the
 correctness
  of these files? Example, if one of the intermediate snapshot file is
  corrupt.
 
  - The Admin's guide says Using older log and snapshot files, you can
 look
  at the previous state of ZooKeeper servers and even restore that state.
 The
  LogFormatter class allows an administrator to look at the transactions in
 a
  log. * *Is there a tool that does this for the admin?  The LogFormatter
  only displays the transactions in the log file.
 
  - Has anyone ever had to play with the snapshot files in production?
 
  Thanks in advance.
 
  Regards,
  -Vishal