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From ruslan usifov <ruslan.usi...@gmail.com>
Subject Re: get dinamicsnith info from php
Date Mon, 14 May 2012 14:41:18 GMT
Sorry for my bad english.


I want to solve follow problem. For example we down one node for
maintenance reason, for a long time (30 min). Now we use TSocketPool for
polling connection to cassandra, but this poll implementation is as i think
not so good, it have a custom parameter setRetryInterval, with allow off
broken node (now we set i to 10sec), but this mean that every 10sec pool
will try to connet down node (i repeat we shutdown node for maintance
reason), because it doesn't know node dead or node, but cassandra cluster
know this, and this connection attempt is senselessly, also when node make
compact it can be heavy loaded, and can't serve client reqest very good (at
this moment we can got little increase of avg backend responce time)

2012/5/14 Viktor Jevdokimov <Viktor.Jevdokimov@adform.com>

>  I’m not sure, that selecting node upon DS is a good idea. First of all
> every node has values about every node, including self. Self DS values are
> always better than others.****
>
> ** **
>
> For example, 3 nodes RF=2:****
>
> ** **
>
> N1****
>
> N2****
>
> N3****
>
> N1****
>
> 0.5ms****
>
> 2ms****
>
> 2ms****
>
> N2****
>
> 2ms****
>
> 0.5ms****
>
> 2ms****
>
> N3****
>
> 2ms****
>
> 2ms****
>
> 0.5ms****
>
> ** **
>
> We have monitored many Cassandra counters, including DS values for every
> node, and graphs shows that latencies is not about load.****
>
> ** **
>
> So the strategy should be based on use case, node count, RF, replica
> placement strategy, read repair chance, and more, and more…****
>
> ** **
>
> What do you want to achieve?****
>
> ** **
>
> ** **
>
>
>    Best regards / Pagarbiai
> *Viktor Jevdokimov*
> Senior Developer
>
> Email: Viktor.Jevdokimov@adform.com
> Phone: +370 5 212 3063, Fax +370 5 261 0453
> J. Jasinskio 16C, LT-01112 Vilnius, Lithuania
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>
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> *From:* ruslan usifov [mailto:ruslan.usifov@gmail.com]
> *Sent:* Monday, May 14, 2012 16:58
> *To:* user@cassandra.apache.org
> *Subject:* get dinamicsnith info from php****
>
> ** **
>
> Hello
>
> I want to route request from php client to minimaly loaded node, so i need
> dinamicsnitch info and gosip, how can i get this info fro php. Perhaps need
> some daemon that can communicate with cassandra gosip and translate this
> info to php (socket for example)???****
>

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