+1 (binding) Enrico
Il Mer 22 Dic 2021, 13:09 Hang Chen <chenh...@apache.org> ha scritto: > +1 > > Thanks, > Hang > > PengHui Li <peng...@apache.org> 于2021年12月22日周三 19:34写道： > > > > +1 > > > > Penghui > > > > On Wed, Dec 22, 2021 at 7:22 AM Matteo Merli <mme...@apache.org> wrote: > > > > > https://github.com/apache/pulsar/issues/13304 > > > > > > Following the discussion, I have updated the proposal to also include > > > the deprecation and renaming of the config setting name to > > > `metadataSessionExpiredPolicy`. > > > > > > > > > > > > ------- > > > ## Motivation > > > > > > After all the work done for PIP-45 that was already included in 2.8 > and 2.9 > > > releases, it enabled the concept of re-acquirable resource locks and > leader > > > election. > > > > > > Another important change was to avoid doing any deferrable metadata > > > operation > > > when we know that we are not currently connected to the metadata > service. > > > > > > Finally, that enabled to stabilize in 2.9 the configuration setting > that > > > allows > > > brokers to continue operating in a safe mode when the session with > > > ZooKeeper > > > expires. > > > > > > The way it works is that, when we lose a ZooKeeper session, the data > plane > > > will > > > continue to work undisturbed, relying on the BookKeeper fencing to > avoid > > > any > > > inconsistencies. > > > > > > New topics are not able to get started, but existing topics will see no > > > impact. > > > > > > The original intention for shutting down the brokers was to ensure > that we > > > would automatically go back to a consistent state, with respect to > which > > > resources are "owned" in ZooKeeper by a given broker. > > > > > > With the re-acquirable resource locks, that problem was solved and > > > thoroughly > > > tested to be robust. > > > > > > ## Proposed changes > > > > > > In 2.10 release, for the setting: > > > > > > ```properties > > > # There are two policies to apply when broker metadata session > > > expires: session expired happens, "shutdown" or "reconnect". > > > # With "shutdown", the broker will be restarted. > > > # With "reconnect", the broker will keep serving the topics, while > > > attempting to recreate a new session. > > > zookeeperSessionExpiredPolicy=shutdown > > > ``` > > > > > > Deprecate the old setting and rename it to > > > `metadataSessionExpiredPolicy`, with default value set to `reconnect`. > > > >
