Zookeeper Distributed Process Chiefs

Goal

To be able to reliably use zookeeper to control the invocation of a distributed systems applications, allowing there to be 1 'primary' process leader with X backup process leaders (who will become active if the first primary leader either exits successfully or exists incorrectly).

1. Uses zookeeper leader election to attempt to guarantee who is the currently active single process (with-in the limits of zookeeper).
2. Make programs which are potentially unsafe to run simultaneous instances of have the capability to have fail-over instances which will automatically get turned on.

Install

sudo pip-python install -r tools/pip-requires
sudo python setup.py install

Get a zookeeper server up and running.

• http://zookeeper.apache.org/doc/current/zookeeperStarted.html

Example

# Start zookeeper
$ZOOKEEPER_DIR/bin/zkServer.sh start

# On one terminal
solo.py -v  `which python` tools/spinner.py

# On a second terminal
solo.py -v  `which python` tools/spinner.py

Monitoring

# Start zkcli
sudo zkCli.sh -server 127.0.0.1:2181

# Use normal zkCli commands  
get path [watch]
ls path [watch]
set path data [version]
rmr path
delquota [-n|-b] path
quit 
printwatches on|off
create [-s] [-e] path data acl
stat path [watch]
close 
ls2 path [watch]
history 
listquota path
setAcl path acl
getAcl path
sync path
redo cmdno
addauth scheme auth
delete path [version]
setquota -n|-b val path