Zookeeper C client library This package provides a C client interface to Zookeeper server. For the latest information about ZooKeeper, please visit our website at: http://zookeeper.apache.org/ and our wiki, at: https://cwiki.apache.org/confluence/display/ZOOKEEPER Full documentation for this release can also be found in ../../docs/index.html OVERVIEW The client supports two types of APIs -- synchronous and asynchronous. Asynchronous API provides non-blocking operations with completion callbacks and relies on the application to implement event multiplexing on its behalf. On the other hand, Synchronous API provides a blocking flavor of zookeeper operations and runs its own event loop in a separate thread. Sync and Async APIs can be mixed and matched within the same application. The package includes two shared libraries: zookeeper_st and zookeeper_mt. The former only provides the Async API and is not thread-safe. The only reason this library exists is to support the platforms were pthread library is not available or unstable (i.e. FreeBSD 4.x). In all other cases the application developers are advised to link against zookeeper_mt as it includes support for both Sync and Async API. INSTALLATION If you're building the client from a source checkout you need to follow the steps outlined below. If you're building from a release tar downloaded from Apache please skip to step 2. 1) do a "ant compile_jute" from the zookeeper top level directory (.../trunk). This will create a directory named "generated" under src/c. Skip to step 3. 2) unzip/untar the source tarball and cd to the zookeeper-x.x.x/src/c directory 3) change directory to src/c and do a "autoreconf -if" to bootstrap autoconf, automake and libtool. Please make sure you have autoconf version 2.59 or greater installed. If cppunit is installed in a non-standard directory, you need to specify where to find cppunit.m4. For example, if cppunit is installed under /usr/local, run: ACLOCAL="aclocal -I /usr/local/share/aclocal" autoreconf -if 4) do a "./configure [OPTIONS]" to generate the makefile. See INSTALL for general information about running configure. Additionally, the configure supports the following options: --enable-debug enables optimization and enables debug info compiler options, disabled by default --without-syncapi disables Sync API support; zookeeper_mt library won't be built, enabled by default --disable-static do not build static libraries, enabled by default --disable-shared do not build shared libraries, enabled by default --without-cppunit do not build the test library, enabled by default. 5) do a "make" or "make install" to build the libraries and install them. Alternatively, you can also build and run a unit test suite (and you probably should). Please make sure you have cppunit-1.10.x or higher installed before you execute step 4. Once ./configure has finished, do a "make check". It will build the libraries, build the tests and run them. 6) to generate doxygen documentation do a "make doxygen-doc". All documentations will be placed to a new subfolder named docs. By default only HTML documentation is generated. For information on other document formats please use "./configure --help" EXAMPLE/SAMPLE C CLIENT SHELL NOTE: the ZooKeeper C client shell (cli_st and cli_mt) is meant as a example/sample of ZooKeeper C client API usage. It is not a full fledged client and not meant for production usage - see the Java client shell for a fully featured shell. You can test your client by running a zookeeper server (see instructions on the project wiki page on how to run it) and connecting to it using the zookeeper shell application cli that is built as part of the installation procedure. cli_mt (multithreaded, built against zookeeper_mt library) is shown in this example, but you could also use cli_st (singlethreaded, built against zookeeper_st library): $ cli_mt zookeeper_host:9876 To start a client with read-only mode enabled, use the -r flag: $ cli_mt -r zookeeper_host:9876 This is a client application that gives you a shell for executing simple zookeeper commands. Once successfully started and connected to the server it displays a shell prompt. You can now enter zookeeper commands. For example, to create a node: > create /my_new_node To verify that the node's been created: > ls / You should see a list of nodes who are the children of the root node "/". Here's a list of command supported by the cli shell: ls -- list children of a znode identified by . The command set a children watch on the znode. get -- get the value of a znode at set -- set the value of a znode at to create [+e|+s] -- create a znode as a child of znode ; use +e option to create an ephemeral znode, use +s option to create a znode with a sequence number appended to the name. The operation will fail if the parent znode (the one identified by ) doesn't exist. delete -- delete the znode at . The command will fail if the znode has children. sync -- make sure all pending updates have been applied to znode at exists -- returns a result code indicating whether the znode at exists. The command also sets a znode watch. myid -- prints out the current zookeeper session id. quit -- exit the shell. In order to be able to use the zookeeper API in your application you have to 1) remember to include the zookeeper header #include 2) use -DTHREADED compiler option to enable Sync API; in this case you should be linking your code against zookeeper_mt library Please take a look at cli.c to understand how to use the two API types. (TODO: some kind of short tutorial would be helpful, I guess)