Re: Typical Cache Values

[Pranav Prakash]

>
> *
> *
> This is not unusual, but there's also not much reason to give this much
> memory in your case. This is the cache that is hit when a user pages
> through result set. Your numbers would seem to indicate one of two things:
> 1> your window is smaller than 2 pages, see solrconfig.xml,
>
> or
> 2> your users are rarely going to the next page.
>
> this cache isn't doing you much good, but then it's also not using that
> much in the way of resources.
>
>

True it is. Although the queryResultWindowSize is 30, I will be reducing it
to 4 or so. And yes, we have observed that mostly people don't go beyond
the first page



> > documentCache
> >
> > lookups : 17647360
> > hits : 11935609
> > hitratio : 0.67
> > inserts : 5711851
> > evictions : 5707755
> > size : 4096
> > warmupTime : 0
> > cumulative_lookups : 19009142
> > cumulative_hits : 12813630
> > cumulative_hitratio : 0.67
> > cumulative_inserts : 6195512
> > cumulative_evictions : 6187460
> >
>
> Again, this is actually quite reasonable. This cache
> is used to hold document data, and often doesn't have
> a great hit ratio. It is necessary though, it saves quite
> a bit of disk seeks when servicing a single query.
>
> >
> > fieldValueCache
> >
> > lookups : 0
> > hits : 0
> > hitratio : 0.00
> > inserts : 0
> > evictions : 0
> > size : 0
> > warmupTime : 0
> > cumulative_lookups : 0
> > cumulative_hits : 0
> > cumulative_hitratio : 0.00
> > cumulative_inserts : 0
> > cumulative_evictions : 0
> >
>
> Not doing much in the way of faceting, are you?
>
>
No. We don't facet results


> >
> > filterCache
> >
> > lookups : 30059278
> > hits : 28813869
> > hitratio : 0.95
> > inserts : 1245744
> > evictions : 1245232
> > size : 512
> > warmupTime : 28005
> > cumulative_lookups : 32155745
> > cumulative_hits : 30845811
> > cumulative_hitratio : 0.95
> > cumulative_inserts : 1309934
> > cumulative_evictions : 1309245
> >
> >
>
> Not a bad hit ratio here, this is where
> fq filters are stored. One caution here;
> it is better to break out your filter
> queries where possible into small chunks.
> Rather than write fq=field1:val1 AND field2:val2,
> it's better to write fq=field1:val1&fq=field2:val2
> Think of this cache as a map with the query
> as the key. If you write the fq the first way above,
> subsequent fqs for either half won't use the cache.
>

That was a great advise. We do use the former approach but going forward we
would stick to the latter one.

Thanks,

Pranav

Re: Typical Cache Values

[Erick Erickson]

See below...

On Tue, Feb 7, 2012 at 8:21 AM, Pranav Prakash  wrote:
> Based on the hit ratio of my caches, they seem to be pretty low. Here they
> are. What are typical values of yours production setup? What are some of
> the things that can be done to improve the ratios?
>
> queryResultCache
>
> lookups : 3234602
> hits : 496
> hitratio : 0.00
> inserts : 3234239
> evictions : 3230143
> size : 4096
> warmupTime : 8886
> cumulative_lookups : 3465734
> cumulative_hits : 526
> cumulative_hitratio : 0.00
> cumulative_inserts : 3465208
> cumulative_evictions : 3457151
>
>

This is not unusual, but there's also not much reason to give this much
memory in your case. This is the cache that is hit when a user pages
through result set. Your numbers would seem to indicate one of two things:
1> your window is smaller than 2 pages, see solrconfig.xml,

or
2> your users are rarely going to the next page.

this cache isn't doing you much good, but then it's also not using that
much in the way of resources.

> documentCache
>
> lookups : 17647360
> hits : 11935609
> hitratio : 0.67
> inserts : 5711851
> evictions : 5707755
> size : 4096
> warmupTime : 0
> cumulative_lookups : 19009142
> cumulative_hits : 12813630
> cumulative_hitratio : 0.67
> cumulative_inserts : 6195512
> cumulative_evictions : 6187460
>

Again, this is actually quite reasonable. This cache
is used to hold document data, and often doesn't have
a great hit ratio. It is necessary though, it saves quite
a bit of disk seeks when servicing a single query.

>
> fieldValueCache
>
> lookups : 0
> hits : 0
> hitratio : 0.00
> inserts : 0
> evictions : 0
> size : 0
> warmupTime : 0
> cumulative_lookups : 0
> cumulative_hits : 0
> cumulative_hitratio : 0.00
> cumulative_inserts : 0
> cumulative_evictions : 0
>

Not doing much in the way of faceting, are you?

>
> filterCache
>
> lookups : 30059278
> hits : 28813869
> hitratio : 0.95
> inserts : 1245744
> evictions : 1245232
> size : 512
> warmupTime : 28005
> cumulative_lookups : 32155745
> cumulative_hits : 30845811
> cumulative_hitratio : 0.95
> cumulative_inserts : 1309934
> cumulative_evictions : 1309245
>
>

Not a bad hit ratio here, this is where
fq filters are stored. One caution here;
it is better to break out your filter
queries where possible into small chunks.
Rather than write fq=field1:val1 AND field2:val2,
it's better to write fq=field1:val1&fq=field2:val2
Think of this cache as a map with the query
as the key. If you write the fq the first way above,
subsequent fqs for either half won't use the cache.

Best
Erick

>
>
> *Pranav Prakash*
>
> "temet nosce"
>
> Twitter  | Blog  |
> Google 

Typical Cache Values

[Pranav Prakash]

Based on the hit ratio of my caches, they seem to be pretty low. Here they
are. What are typical values of yours production setup? What are some of
the things that can be done to improve the ratios?

queryResultCache

lookups : 3234602
hits : 496
hitratio : 0.00
inserts : 3234239
evictions : 3230143
size : 4096
warmupTime : 8886
cumulative_lookups : 3465734
cumulative_hits : 526
cumulative_hitratio : 0.00
cumulative_inserts : 3465208
cumulative_evictions : 3457151


documentCache

lookups : 17647360
hits : 11935609
hitratio : 0.67
inserts : 5711851
evictions : 5707755
size : 4096
warmupTime : 0
cumulative_lookups : 19009142
cumulative_hits : 12813630
cumulative_hitratio : 0.67
cumulative_inserts : 6195512
cumulative_evictions : 6187460


fieldValueCache

lookups : 0
hits : 0
hitratio : 0.00
inserts : 0
evictions : 0
size : 0
warmupTime : 0
cumulative_lookups : 0
cumulative_hits : 0
cumulative_hitratio : 0.00
cumulative_inserts : 0
cumulative_evictions : 0


filterCache

lookups : 30059278
hits : 28813869
hitratio : 0.95
inserts : 1245744
evictions : 1245232
size : 512
warmupTime : 28005
cumulative_lookups : 32155745
cumulative_hits : 30845811
cumulative_hitratio : 0.95
cumulative_inserts : 1309934
cumulative_evictions : 1309245




*Pranav Prakash*

"temet nosce"

Twitter  | Blog  |
Google