On 05/16/2012 01:24 PM, R. Verlangen wrote:
Hi there,
I'm using HAProxy for PHP projects to take care of this. It improved
connection pooling enormous on the client side: with preserving
failover capabilities. Maybe that is something for you to use in
combination with PHP.
I already use it exactly like this :)
But i don't think it's a good solution. And it's totally unaware of
thrift/cassandra protocol, it's was pretty well discussed here
http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Cassandra-amp-HAProxy-td5473144.html
I even see the plain tcp healchecks failing from time to time for no reason.
I'm planning to make it a bit smarter with localhost http level
healthchecks - where it would make a cassandra write to CF in
keyspace wich has replication of 1, and will write to a key that maps
to the specific cassandra node being checked by healthcheck (of course
the keys need to be recaclulated each time the cluster is rebalanced).
But IMHO it's very very ugly hack, and not as reliable as real smart
proxy which is way more superior and efficient (especially if it could
do the reads/writes coordination itself).
Haproxy also has an issue that then once of the backend ip changes
(which happens often in clouds) it's has to be restarted to resolve the
the correct hostname,
though it looks like Willy is finally seriously considering to implement
more dynamic for hostnames lookups (which was not the case about a year
ago then I asked for such feature)
the problem was is discussed here recently -
http://marc.info/?l=haproxy&m=133559164408814&w=1
haproxy has some more issues - i don't remember off top of my head.
Smart proxy would simply not have all those issues, as it's aware of the
ring state and the protocol and if smaprt proxy was the cassandra
itself then it would have all the needed features tested and reliable at
no effort.
Thanks
Alex
Good luck!
2012/5/16 Piavlo <lolitus...@gmail.com <mailto:lolitus...@gmail.com>>
Hi,
I'm interested in using some smart proxy cassandra process that
could act as coordinator node and be aware of cluster state.
And run this smart proxy cassandra process on each client side
host where the application(php) with short lived cassandra
connections runs.
Besides being aware of cluster state if it could act as
coordinator node it would save unneeded network trips.
And maybe even have an option to take care of hinted handoffs.
IMHO the best candidate for this is the cassandra itself (like
it's done in elasticsearch
http://www.elasticsearch.org/guide/reference/modules/node.html)
I also see there was a work done in this direction at
https://issues.apache.org/jira/browse/CASSANDRA-535
So maybe this is something that is already usable?
Or maybe there is some third party project that could be used as
smart cassandra proxy?
Thanks
Alex
--
With kind regards,
Robin Verlangen
www.robinverlangen.nl <http://www.robinverlangen.nl>
