1) Yes, I believe that roughly if the follower doesn't hear from the leader it will go from state FOLLOWING to state LOOKING, which starts on that server a request for leader election
2) you can have ZK set to support read-only mode, which will allow reads from read-only clients even when disconnected from quorum, see below. 3) Yes, when the follower loses quorum for whatever reason it will disconnect the clients, which will get a CONNECTION_LOSS error and start looking for another server to connect to. I'm actually not sure what happens if you have a client that is in readonlymode connected to a server that allows readonlymode, perhaps it does not get disconnected at this time but you'd have to look at the docs. Read Only Mode Server (Java system property: *readonlymode.enabled*) *New in 3.4.0:* Setting this value to true enables Read Only Mode server support (disabled by default). ROM allows clients sessions which requested ROM support to connect to the server even when the server might be partitioned from the quorum. In this mode ROM clients can still read values from the ZK service, but will be unable to write values and see changes from other clients. See ZOOKEEPER-784 for more details. On Jul 5, 2016 4:50 PM, "Paul K. Harter, Jr." <[email protected]> wrote: > Apologies if this has been discussed previously, but I have a few questions > > on the handling of SyncLimit. > > > > 1) does a follower keep track of SyncLimit and initiate election if it > has > not heard from the Leader for SyncLimit, or what triggers Leader Election? > > 2) can a follower continue to serve "read" requests during Leader > Election, > or does Leader Election pause all client activity?? > > 3) does a follower give its clients an explicit notification telling > them to find > another server to help ensure that their sessions do not time out?? > If so, when? SyncLimit?? > > > > Thanks > > > > paul > >
