zope.server wrapper that registers with ZooKeeper
zc.zkzopeserver provides a wrapper for the zope.server WSGI runner that registers with ZooKeeper. By registering with ZooKeeper, you can let the operating system assign ports and have clients find your server by looking in ZooKeeper.
The wrapper is used in a past-deploy configuration file:
[server:main] use = egg:zc.zkzopeserver zookeeper = zookeeper.example.com:2181 path = /fooservice/providers
The wrapper supports the following options:
- required ZooKeeper connection string
required path at which to register your server
Your server is registered by adding a ZooKeeper ephemeral node as a child of the path with the server address as the name.
- host name or ip to listen on, defaulting to ‘’
- The port to listen on, defaulting to 0
- A ZooKeeper session timeout in milliseconds
- The size of the thread pool, defaulting to 1
A zc.monitor server address.
The value is an address of the form HOST:PORT. See Monitor server below. (Host can be empty to listen on all interfaces.)
This can be one of:
A logging level name (CRITICAL, ERROR, WARNING, INFO, or DEBUG), or
A ZConfig loggers-definition string.
If the configuration includes format strings, you’ll need to use double dollar signs rather than %, as in:
This is necessary due to the use of string formats in the Paste Deployment configuration syntax.
The zc.monitor package provides a simple extensible command server for gathering monitoring data or providing run-time control of servers. If zc.monitor is in the Python path, zc.zkzopeserver can start a monitor server and make it’s address available as the monitor property of a server’s ephemeral port. To see how this works, let’s update the earler example:
[server:main] use = egg:zc.zkzopeserver zookeeper = zookeeper.example.com:2181 path = /fooservice/providers monitor_server = 127.0.0.1:0
When our web server is running, the /fooservice/providers node would look something like:
/providers /126.96.36.199:61181 monitor = u'127.0.0.1:61182' pid = 4525
Some notes on the monitor server:
- A monitor server won’t be useful unless you’ve registered some command plugins.
- zc.monitor isn’t a dependency of zc.zkzopeserver and won’t be in the Python path unless you install it.
The package zc.zservertracelog extends zope.server to provide support for “trace” logs that have multiple log entries per web request as a request goes through various stages.
If you want to use zc.zservertraeslog with zc.zkzopeserver, make sure zc.zservertracelog is in your Python path and include the zservertracelog option in your server section:
[server:main] use = egg:zc.zkzopeserver zookeeper = zookeeper.example.com:2181 path = /fooservice/providers monitor_server = 127.0.0.1:0 zservertracelog = true
- Added logging-configuration support.
- Fixed: servers were registered with the host information returned by socket.getsockname(), which was unhelpful.
- Fixed: Killing a server (with SIGTERM) didn’t shut down the ZooKeeper connection cleanly, causing a delay in removing registered ephemeral nodes.
Added optional support for using zc.zservertracelog to generate trace logs.