hey jay, we both are sailing in same boat!! I am in process of shifting from pecl/memcache to pecl/memcached too. I have done some testing yesterday itself, and have some feedback which might help you.
First of all, look very seriously and carefully which hashing policy you were using(with memcache) and which one you have used(memcached) currently dusring you testing. Memcache uses Traditional hashing policy i.e. Modula(depends upon no. of servers) by default and it also supports *consistent* hashing policy. So, it was *only* coincidence that you get key from memcached which was set by memcache, that means key was mapped to same server. So as far as both the libraris uses same Hashing Policy you will get same result, ideally (but i doubt as both libraries have their implementation for Hashing Algorithms), But if you have used diff Hashing policies in both clients then you CANT get same results. Secondly, i would recommend don't use both the clients together, do your full fledged testing with memcached on ur test servers and then if satisfied make another wrapper class and use it. Beware, you cant avoid a Memcache Server Restart in this case, as your keys will be remapped, its better to FLUSH ALL and Warm the Cache again, i can understand the pain it may cause as im having only 2GB of data still thinking of Gracefull way to do it. On Feb 3, 6:07 am, Jay Paroline <[email protected]> wrote: > Fortunately, way back when we started using memcache I wrote a wrapper > for it to handle some of the more tedious stuff for me automatically. > All our code uses that wrapper class, so I just had to change the one > class to swap out extensions. :) > > Unfortunately in our testing we are seeing some weirdness. If we set a > key from pecl/memcache we can get it from pecl/memcached, but if we > set it from pecl/memcached, we can't retrieve it from pecl/memcache. I > was hoping that I just missed something in the long list of options > that would make it fully backwards compatible. > > Jay > > On Feb 2, 10:34 am, Brian Moon <[email protected]> wrote: > > > The syntax differences don't lend themselves to being swapped out that > > easily. Unless you are going to do a full code roll out to one set of > > servers and not another, I don't think this is too easy. > > > They have different compression settings and I am not sure if they set > > the same flag when sending compressed data. I have not had a reason to > > look into it. > > > A simple test would tell you for sure. Just try it out on your test > > systems and see how it works. Report back. > > > Brian. > > --------http://brian.moonspot.net/ > > > On 2/1/10 11:51 PM, Jay Paroline wrote: > > > > Hi all, > > > > We're in the process of switching from the pecl memcache extension to > > > the pecl memcached extension, but we would like to start out by doing > > > a very limited rollout of the memcached extension so we can compare > > > performance and make sure everything is working as expected. > > > The documentation about the hashing/failover strategies used by the > > > memcache extension is extremely limited. Does anyone know which > > > settings I should use for so that pecl/memcache and pecl/memcached > > > choose the same servers for each key? Should it be considered > > > generally safe to have both clients working on the same keys? > > > > Thanks, > > > > Jay
