soft commit through leader

[Gopal Jee <zg...@gmail.com>]

hi
wanted to know, when we do soft commit through configuration in
solrconfig.xml,  will different replicas commit at different point of time
depending upon when the replica started...or will leader send commit to all
replicas at same time as per commit interval set in solrconfig.

thanks
gopal

Re: soft commit through leader

[Erick Erickson <er...@gmail.com>]

In a word "yes". The Solr servers are independently keeping their own
timers and one could trip on replica X while an update was in
transmission from the leader say. Or any one of a zillion other timing
conditions. In fact, this is why the indexes will have different
segments on replicas in a slice, the hard commit can be triggered at
different wall-clock times.

But do note that this isn't as much an issue as you might think. The
timer is started when the first update is sent to Solr. So, in the
scenario where you start up all your nodes, the timer starts when you
issue the first commit, i.e. probably within a few milliseconds of
each other. This might still be an issue, but the gap isn't that wide.
Solr promises _eventual_ consistency....

If you need to control this, if you issue a soft commit from a client
(URL, SolrJ client, curl, etc) then it _is_ distributed to all
replicas in a collection at that point in time.

Best,
Erick

On Tue, May 19, 2015 at 3:43 AM, Gopal Jee <zg...@gmail.com> wrote:
> hi
> wanted to know, when we do soft commit through configuration in
> solrconfig.xml,  will different replicas commit at different point of time
> depending upon when the replica started...or will leader send commit to all
> replicas at same time as per commit interval set in solrconfig.
>
> thanks
> gopal