RE: Read-your-writes consistency?
Thank you very much for the quick answer, Patrick. Kind regards, Marc > -Original Message- > From: Patrick Hunt [mailto:ph...@apache.org] > Sent: Dienstag, 14. Juli 2009 18:28 > To: zookeeper-user@hadoop.apache.org > Subject: Re: Read-your-writes consistency? > > Yes, this is a strong guarantee: > http://hadoop.apache.org/zookeeper/docs/current/zookeeperProgr > ammers.html#ch_zkGuarantees > > Sync is only necessary if client A makes a change, then > client B wishes to read that change with guarantee that it > will see the successfully applied change previously made by A > (this is typically only an issue if A & B communicate through > some non-zk channel, such as direct socket connection btw A & B). > > Patrick > > Marc Frei wrote: > > Dear ZooKeeper users, > > > > a short question about ZooKeeper's consistency model: > > > > Does ZooKeeper support "read-your-writes consistency"? E.g., after > > having created a node, will the same client always find the newly > > created node via getChildren? If yes, is this specified > behavior the > > client can rely on? Or is it better to always call sync in order to > > enforce consistency? > > > > Thanks in advance and kind regards, > > > > Marc >
Re: Read-your-writes consistency?
Yes, this is a strong guarantee: http://hadoop.apache.org/zookeeper/docs/current/zookeeperProgrammers.html#ch_zkGuarantees Sync is only necessary if client A makes a change, then client B wishes to read that change with guarantee that it will see the successfully applied change previously made by A (this is typically only an issue if A & B communicate through some non-zk channel, such as direct socket connection btw A & B). Patrick Marc Frei wrote: Dear ZooKeeper users, a short question about ZooKeeper's consistency model: Does ZooKeeper support "read-your-writes consistency"? E.g., after having created a node, will the same client always find the newly created node via getChildren? If yes, is this specified behavior the client can rely on? Or is it better to always call sync in order to enforce consistency? Thanks in advance and kind regards, Marc
Read-your-writes consistency?
Dear ZooKeeper users, a short question about ZooKeeper's consistency model: Does ZooKeeper support "read-your-writes consistency"? E.g., after having created a node, will the same client always find the newly created node via getChildren? If yes, is this specified behavior the client can rely on? Or is it better to always call sync in order to enforce consistency? Thanks in advance and kind regards, Marc
