> On Oct. 10, 2014, 10:30 p.m., Ben Mahler wrote:
> > Can writing DIFFs be optional via the construcotr? I'm hoping to initially 
> > leave this off for the Registrar for two reasons:
> > 
> > (1) Upgrading. It would be nice to be able to upgrade the masters 
> > seamlessly with respect to the Registrar:
> >     
> >     Phase 1: Masters can read DIFFs, don't write DIFFs.
> >     Phase 2: Masters write diffs.
> > 
> > If we move directly to phase 2 (as per this patch), then the upgrade of the 
> > masters needs to be done in lock-step to ensure that an old leading master 
> > doesn't come up when there are DIFF entries written, causing unnecessary 
> > failovers. The constructor argument would give us control over this, while 
> > still making it immediately available to users of LogStorage.
> > 
> > (2) Ability to disable diffs. We need to run the Registrar benchmarks for 
> > DIFF enabled LogStorage. However, we'd still like to be able to flip it off 
> > should we encounter issues in a production environment. Without a flag + 
> > constructor argument, we have to roll back to disable it.
> > 
> > Sound reasonable?

Yes. I refactored DIFFS_BETWEEN_SNAPSHOTS from a constant to a value that can 
be passed to the constructor. The default is currently 0, i.e., always 
construct snapshots.


- Benjamin


-----------------------------------------------------------
This is an automatically generated e-mail. To reply, visit:
https://reviews.apache.org/r/24536/#review56243
-----------------------------------------------------------


On Oct. 12, 2014, 5:14 a.m., Benjamin Hindman wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> https://reviews.apache.org/r/24536/
> -----------------------------------------------------------
> 
> (Updated Oct. 12, 2014, 5:14 a.m.)
> 
> 
> Review request for mesos, Ben Mahler and Jie Yu.
> 
> 
> Repository: mesos-git
> 
> 
> Description
> -------
> 
> See summary.
> 
> Note that this hard codes the location of the subversion and Apache Portable 
> Runtime (APR) headers.
> 
> 
> Diffs
> -----
> 
>   src/Makefile.am d503c8df73cda15a9d59254e8265e4a5d0e003a4 
>   src/java/jni/org_apache_mesos_state_LogState.cpp PRE-CREATION 
>   src/java/src/org/apache/mesos/state/LogState.java PRE-CREATION 
>   src/messages/state.proto 59276e55fcbebdb754c20d39b13b402fd11c3dad 
>   src/state/log.hpp 6bd054fcd1cf79a2ad1a59da59c9a903cb25882f 
>   src/state/log.cpp fd8b28a0b5d14f5ba3e6fde4695f6d09acf9c56a 
> 
> Diff: https://reviews.apache.org/r/24536/diff/
> 
> 
> Testing
> -------
> 
> make check
> 
> 
> Thanks,
> 
> Benjamin Hindman
> 
>

Reply via email to