motus / haskell-zookeeper-client Goto Github PK

Apache is incompatible (due to patent terms) with some contributors.

getChildren segfaults whenever I call it on an existing node. Happens whether I use Watch or NoWatch. I'm on 64-bit Ubuntu.

With valueBufferSize set to 20480, I can't get any znodes that are more than 20k.

I'd really like to be able to create znodes as large as zookeeper would allow (1MB).

The module name is currently just Zookeeper. To release this package on hackage, the module name should fit into the hierarchical namespace described here:

http://www.haskell.org/haskellwiki/Hierarchical_module_names

I'm not really sure what the right name should be. Although zookeeper isn't exactly a database, it is similar enough to something like redis, which is in Database.Redis, so maybe it should be Database.Zookeper.

Please let us know :)

There's no documentation, no tests…how do I know which versions of Zookeeper this works with?

Here's a patch that enables -Wall and eliminates a lot (but not all) of the warnings: 0e2d1a7

I'm still getting segfaults occasionally, sometimes "schedule: re-entered unsafely. Perhaps a 'foreign import unsafe' should be 'safe'?"

Here's my scenario to reproduce it:

run zh = do
  (_, stat) <- get zh "/test/A" Watch
  set zh "/test/A" (Just "asdf") (fromIntegral $ stat_version stat)
  return ()

watcher zh event st path = do
    putStrLn $ concat [ show event, ", ", show st, ", ", path ]

Then, just call this with an open ZHandle:

forever $ run zh

If I create a watcher that calls "error", and then use the watcher like this:

zh1 <- init "localhost:2181" watcher 10000
zh2 <- init "localhost:2181" watcher 10000

The program either crashes with a segfault or it hangs. Not really sure what's going on.

Not sure if this is desired behavior or not, but if the ZHandle returned from "init" goes out of scope, the watchers stop working. I can to fork a thread that touches the ZHandle in order to prevent it from being finalized.

When I connect to zookeeper, my watch function receives this event:

Unknown 4294967295

If I change the zooEvent function to use Word32 instead of Int, then the problem is fixed. I am using 64-bit linux.

The commit is in my repo: eacb73e40b296b8fe7a0c96fcace64acb36f973a

What license is this under? zookeeper's apache-2, but I didn't see any license notification anywhere in the project.