Also, since 3.5, there are “container” nodes that auto-delete once emptied of children.
-JZ > On Mar 18, 2016, at 11:49 AM, Flavio Junqueira <[email protected]> wrote: > > It is currently as Jordan says, although it is not entirely unreasonable to > think of memory as cache and keep in memory only the current working set, > possibly using say an SSD to store the remaining part of the state that you > don't want to keep in memory. One key issue here is that if you have a pretty > large state (that you don't want to keep all in memory), then you'll end up > increasing worst-case recovery time. > > We certainly do not have any kind of expiration mechanism for znodes other > than the ephemeral flag, which is associated to sessions. > > -Flavio > >> On 18 Mar 2016, at 16:38, ibrahim El-sanosi <[email protected]> wrote: >> >> Thank you for replaying. >> >> >> Take this example, Zookeeper started on 1/1/2015, and assume ZK servers are >> never crashed. Also, the ZK are very busy, reciveing continusly write >> requests from clients and accordingly snapshots are generated overtime. On >> 1/3/2015, what Znodes will be in memory data tree? do all Znodes still >> store in memory (from 1/1/2015 to 1/3/2015) as there is no crashed occur. >> Or Dsnapshhot is taken the data tree is >> >> >> Note that I am not asking about data in log or snapshoot. I am asking >> about the current data in memory. >> >> On Fri, Mar 18, 2016 at 4:12 PM, Flavio Junqueira <[email protected]> wrote: >> >>> Hi Ibrahim, >>> >>> Are you asking about how we compact old logs? We do it by taking snapshots >>> so that upon recovery, we only load the latest snapshot and replay the txn >>> log from the snapshot tag. The snapshot tag is the last zxid committed when >>> we start producing the snapshot. >>> >>> We don't actually delete anything, though, unless you intentionally turn >>> on auto purge: >>> >>> https://zookeeper.apache.org/doc/trunk/zookeeperAdmin.html#sc_administering >>> < >>> https://zookeeper.apache.org/doc/trunk/zookeeperAdmin.html#sc_administering >>>> >>> >>> -Flavio >>> >>>> On 18 Mar 2016, at 16:05, ibrahim El-sanosi <[email protected]> >>> wrote: >>>> >>>> Hi all, >>>> >>>> Assume the Zookeeper have been running for about one year (from 1/1/2015 >>>> until now), how does ZooKeeper deal with old delivered write requests (To >>>> optimize a memory used) (say from 1/1/2015 to 03/04/2015). I am assuming >>>> the old delivered request are no longer used. >>>> >>>> On the other words, what strategy ZK does to find and delete unused >>> Znodes? >>>> >>>> Ibrahim >>> >>> >
