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From "R. Verlangen" <ro...@us2.nl>
Subject Re: get dinamicsnith info from php
Date Mon, 14 May 2012 20:28:16 GMT
I struggled with this before and decided to use HAProxy which suits my
needs, you can read a little more about it at my personal blog:

http://www.robinverlangen.nl/index/view/4fa902c1596cb-44a627/how-to-solve-the-pain-of-stateless-php-with-cassandra.html


Good luck with it!

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

>  Let say you have 8 nodes cluster with replication factor 3. If one node
> is down, for its token range you have only 2 nodes left, not 7, which can
> process you requests – other nodes will forward requests to the nearest
> (depends on snitch) or with lower latency (depends on dynamic snitch) of 2
> remaining.****
>
> ** **
>
> I have no idea about PHP and its multithreading capabilities, if it’s
> impossible to run background thread to return dead endpoint to the list,
> instead of checking it on HTTP request thread, you’re stacked. For the
> lower latencies dynamic snitch already do a job for you, selecting a node
> with lower latencies.****
>
> ** **
>
> If you’d like Cassandra to avoid forwarding requests to appropriate node,
> but making a direct request to a node where data is, you need smarter
> client, capable to select node by key and other things to do to achieve
> this.****
>
> ** **
>
> ** **
>
>
>    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
> Follow us on Twitter: @adforminsider <http://twitter.com/#!/adforminsider>
> What is Adform: watch this short video <http://vimeo.com/adform/display>
>  [image: Adform News] <http://www.adform.com>
>
> Disclaimer: The information contained in this message and attachments is
> intended solely for the attention and use of the named addressee and may be
> confidential. If you are not the intended recipient, you are reminded that
> the information remains the property of the sender. You must not use,
> disclose, distribute, copy, print or rely on this e-mail. If you have
> received this message in error, please contact the sender immediately and
> irrevocably delete this message and any copies.
>
> *From:* ruslan usifov [mailto:ruslan.usifov@gmail.com]
> *Sent:* Monday, May 14, 2012 17:41
> *To:* user@cassandra.apache.org
> *Subject:* Re: get dinamicsnith info from php****
>
> ** **
>
> 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****
>
> Follow us on Twitter: @adforminsider<http://twitter.com/#%21/adforminsider>
> ****
>
> What is Adform: watch this short video <http://vimeo.com/adform/display>**
> **
>
> [image: Adform News] <http://www.adform.com>****
>
>
> Disclaimer: The information contained in this message and attachments is
> intended solely for the attention and use of the named addressee and may be
> confidential. If you are not the intended recipient, you are reminded that
> the information remains the property of the sender. You must not use,
> disclose, distribute, copy, print or rely on this e-mail. If you have
> received this message in error, please contact the sender immediately and
> irrevocably delete this message and any copies. ****
>
> ** **
>
> *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)???****
>
> ** **
>



-- 
With kind regards,

Robin Verlangen
www.robinverlangen.nl

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