Re: Limit IO while running solr backup

[Pierre Salagnac]

Hi Saksham,
What Solr version do you run?

With SOLR-16879 in Solr 9.4, a new throttling was added to limit the number
of concurrent backups per node. If I recall well, the default is 5 per
node. Before this fix, all the replica snapshots were started concurrently.

As far as I know, there is no mechanism to specifically limit IOs, but I
achieved the same by limiting the number of snapshots concurrently done.


Le mer. 10 juil. 2024 à 08:27, Saksham Gupta
 a écrit :

> Hi All,
> Pinging again for some assistance!
>
> On Tue, Jul 9, 2024 at 4:02 PM Saksham Gupta 
> wrote:
>
> > Hi All,
> >
> > As an effort to enhance disaster recovery for solr, we have started a
> solr
> > backup process on a daily basis. The backup runs for each replica one
> after
> > the other, after which an integrity check is executed to check if the
> index
> > is having no faults.
> >
> > Although, throughout the backup, we experience high io wait on production
> > servers as complete data of 25 gb is being read [size of each shard is
> ~25
> > gb]. The backup executes daily at night 3 AM [backup for each replica
> runs
> > sequentially] and write is done on a separate disc, still response time
> > takes a significant hit, thereby increasing the number of timeouts and
> 5xx.
> >
> > Is there a way to limit the io so that backup is done at a slower pace
> > keeping the response time and other metrics intact?
> >
>

Re: Searching for synonyms

[Chris Hostetter]

: I can't search for tera* instead of terra*, I think there is also another 
problem.


https://solr.apache.org/guide/solr/latest/indexing-guide/analyzers.html#analysis-for-multi-term-expansion

> In some types of queries (i.e., Prefix, Wildcard, Regex, etc.) the input 
> provided by the user is not natural language intended for Analysis. 
> Things like Synonyms or Stop word filtering do not work in a logical way 
> in these types of Queries.
>
> ...
> 
> For most use cases, this provides the best possible behavior, but if you  
> wish for absolute control over the analysis performed on these types of 
> queries, you may explicitly define a multiterm analyzer to use, such as 
> in the following example:

Note that while defining a 'multiterm' analyzer that uses 
SynonymGraphFilterFactory may give you the results you are looking for in 
your "tera*" example, it is probably not going to work the way most people 
expect in non trivial sitautions involving non trivial synonyms.


-Hoss
http://www.lucidworks.com/