Session handler

[Gerry]

I have been looking for a PHP session handler that will satisfy the
requirements of the project I'm working on, but was not yet able to
find the perfect match.

More specifically, it should have these features:

* PHP extension
* Open source
* Actively maintained
* Decent performance
* Scalable
* Authentication
* Replication and failover with at least two nodes
* Not overly complicated

Note that I do need authentication, but not necessarily encryption. I
do not trust all people having access to the network, but I do trust the
network hardware.

By replication and failover I mean that I will have two instances of
the backend which should replicate to each other, ideally in a master-
master configuration. If one of them fails the other one should be as
up to date as possible and take over all tasks within seconds. I hope
to find a

Some of the solutions I have looked at, but which did not fit the
requirements entirely:

- files, backed by an NFS share or glusterfs

This worked more or less, but had several problems. NFS has locking
issues, glusterfs lacked performance.

- memcached with repcached patch and SASL enabled

This looked promising. Although the repcached patch seems abandoned, I
could apply it to the Debian wheezy package (memcached 1.4.13).
Replication and failover feel solid, just restart the failed memcache
node and it will replicate the content of the other.

The issue is that the repcached patch does not support memcached's
binary protocol, and using SASL requires the binary protocol.

Other than that, this is exactly what I am looking for.

- redis

This works, but replication and failover isn't all that easy to set up
and maintain. Promoting a node to master, re-populating a the failed
node when it comes back up, ... . With repcached, this was done
automatically.

- riak

This works too, but the authentication is overly complicated and the
PHP extension does not seem to support authentication.

I am currently out of ideas. Can anyone point me to other solutions I
might not have looked at yet?

Thanks!