I suspect this is a bug with the sync call and session moved (the code path for sync is a bit special). Please enter a JIRA for this. Thanks.

Patrick

On 08/05/2010 01:20 PM, Vishal K wrote:
Hi All,

I am seeing a lot of these messages in our application. I would like to know
if I am doing something wrong or this is a ZK bug.

Setup:
- Server environment:zookeeper.version=3.3.0-925362
- 3 node cluster
- Each node has few clients that connect to the local server using 127.0.0.1
as the host IP.
- The application first forms a ZK cluster. Once the ZK cluster is formed,
each node establish sessions with local ZK servers. The clients do not know
about remote server so sessions are always with the local server.

As soon as ZK clients connected to their respective follower, the ZK leader
starts spitting the following messages:

2010-07-01 10:55:36,733 - INFO  [ProcessThread:-1:preprequestproces...@405]
- Got user-level KeeperException when processing sessionid:0x298d3b1fa90000
type:sync: cxid:0x6 zxid:0xfffffffffffffffe txntype:unknown reqpath:/ Error
Path:null Error:KeeperErrorCode = Session moved
2010-07-01 10:55:36,748 - INFO  [ProcessThread:-1:preprequestproces...@405]
- Got user-level KeeperException when processing sessionid:0x298d3b1fa90000
type:sync: cxid:0x9 zxid:0xfffffffffffffffe txntype:unknown reqpath:/ Error
Path:null Error:KeeperErrorCode = Session moved
2010-07-01 10:55:36,755 - INFO  [ProcessThread:-1:preprequestproces...@405]
- Got user-level KeeperException when processing sessionid:0x298d3b1fa90000
type:sync: cxid:0xb zxid:0xfffffffffffffffe txntype:unknown reqpath:/ Error
Path:null Error:KeeperErrorCode = Session moved
2010-07-01 10:55:36,795 - INFO  [ProcessThread:-1:preprequestproces...@405]
- Got user-level KeeperException when processing sessionid:0x298d3b1fa90000
type:sync: cxid:0x10 zxid:0xfffffffffffffffe txntype:unknown reqpath:/ Error
Path:null Error:KeeperErrorCode = Session moved
2010-07-01 10:55:36,850 - INFO  [ProcessThread:-1:preprequestproces...@405]
- Got user-level KeeperException when processing sessionid:0x298d3b1fa90001
type:sync: cxid:0x1 zxid:0xfffffffffffffffe txntype:unknown reqpath:/ Error
Path:null Error:KeeperErrorCode = Session moved
2010-07-01 10:55:36,910 - INFO  [ProcessThread:-1:preprequestproces...@405]
- Got user-level KeeperException when processing sessionid:0x298d3b1fa90000
type:sync: cxid:0x1b zxid:0xfffffffffffffffe txntype:unknown reqpath:/ Error
Path:null Error:KeeperErrorCode = Session moved
2010-07-01 10:55:36,920 - INFO  [ProcessThread:-1:preprequestproces...@405]
- Got user-level KeeperException when processing sessionid:0x298d3b1fa90000
type:sync: cxid:0x20 zxid:0xfffffffffffffffe txntype:unknown reqpath:/ Error
Path:null Error:KeeperErrorCode = Session moved
2010-07-01 10:55:37,019 - INFO  [ProcessThread:-1:preprequestproces...@405]
- Got user-level KeeperException when processing sessionid:0x298d3b1fa90000
type:sync: cxid:0x29 zxid:0xfffffffffffffffe txntype:unknown reqpath:/ Error
Path:null Error:KeeperErrorCode = Session moved
2010-07-01 10:55:37,030 - INFO  [ProcessThread:-1:preprequestproces...@405]
- Got user-level KeeperException when processing sessionid:0x298d3b1fa90000
type:sync: cxid:0x2c zxid:0xfffffffffffffffe txntype:unknown reqpath:/ Error
Path:null Error:KeeperErrorCode = Session moved
2010-07-01 10:55:37,035 - INFO  [ProcessThread:-1:preprequestproces...@405]
- Got user-level KeeperException when processing sessionid:0x298d3b1fa90000
type:sync: cxid:0x2e zxid:0xfffffffffffffffe txntype:unknown reqpath:/ Error
Path:null Error:KeeperErrorCode = Session moved
2010-07-01 10:55:37,065 - INFO  [ProcessThread:-1:preprequestproces...@405]
- Got user-level KeeperException when processing sessionid:0x298d3b1fa90000
type:sync: cxid:0x33 zxid:0xfffffffffffffffe txntype:unknown reqpath:/ Error
Path:null Error:KeeperErrorCode = Session moved
2010-07-01 10:55:38,840 - INFO  [ProcessThread:-1:preprequestproces...@405]
- Got user-level KeeperException when processing sessionid:0x298d3b1fa90001
type:sync: cxid:0x4 zxid:0xfffffffffffffffe txntype:unknown reqpath:/ Error
Path:null Error:KeeperErrorCode = Session moved
20

These sessions were established on the follower:
2010-07-01 08:59:09,890 - INFO  [CommitProcessor:0:nioserverc...@1431] -
Established session 0x298d3b1fa90000 with negotiated timeout 9000 for client
/127.0.0.1:50773
2010-07-01 08:59:09,890 - INFO
[SvaDefaultBLC-SendThread(localhost.localdom:2181):clientcnxn$sendthr...@701]
- Session establishment complete on server localhost.localdom/127.0.0.1:2181,
sessionid = 0x298d3b1fa90000, negotiated timeout = 9000


The server is spitting out these messages for every session that it does not
own  (session established by clients with followers). The messages are
always seen for a sync request.
No other issues are seen with the cluster. I am wondering what would be the
cause of this problem? Looking at PrepRequestProcessor, it seems like this
message is printed when the owner of the request is not same as session
owner. But in our application this should never happen since clients always
connect to its local server.

Any ideas?

Thanks.
-Vishal

Reply via email to