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From James Taylor <jamestay...@apache.org>
Subject Re: hotspot in System.catalog table
Date Fri, 13 Apr 2018 06:06:08 GMT
No, that won’t make a difference.

On Thu, Apr 12, 2018 at 10:51 PM anil gupta <anilgupta84@gmail.com> wrote:

> Thanks for quick reply, James. We will look into UPDATE_CACHE_FREQUENCY
> property. If we just replace PS with Statement, will it fix the
> problem(AFAIK, Statement is not compiled)?
>
> On Thu, Apr 12, 2018 at 10:43 PM, James Taylor <jamestaylor@apache.org>
> wrote:
>
>> Try setting the UPDATE_CACHE_FREQUENCY table property (and configuring
>> the phoenix.default.update.cache.frequency system-wide property). That'll
>> prevent pinging the region hosting SYSTEM.CATALOG every time a query is
>> compiled. We've found value of even 5 seconds makes a big difference. For
>> more on that, see here[1] and here[2].
>>
>> In the future, we'll let the SYSTEM.CATALOG table span multiple regions -
>> keep an eye on PHOENIX-3534.
>>
>> Thanks,
>> James
>>
>> [1] https://phoenix.apache.org/#Altering
>> [2] https://phoenix.apache.org/language/index.html#options
>>
>> On Thu, Apr 12, 2018 at 10:32 PM, anil gupta <anilgupta84@gmail.com>
>> wrote:
>>
>>> Hi All,
>>>
>>> System.catalog table seems to be single region table(correct?). We are
>>> currently facing a problem of hotspot on System.catalog table.
>>> One of our app does around 4-5k select queries/sec. And, It is creating
>>> a new preparedstatement everytime. I suspect that while instantiating a new
>>> preparedstatement(contrary to Statement), system.catalog table is queried
>>> first. Hence, it is resulting into hotspotting. Is my analysis correct?
>>>
>>> (I have already suggested my colleagues to try using Statement instead
>>> of PS if they have to create a new one everytime.)
>>>
>>> --
>>> Thanks & Regards,
>>> Anil Gupta
>>>
>>
>>
>
>
> --
> Thanks & Regards,
> Anil Gupta
>

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