What is the zNode data limit size for Apache ZooKeeper?

1GB? 10MB? 1KB? zNode Limit = 1MB. This is the default size of a single zNode or key/value pair within ZooKeeper.  It should be noted that both the Key and the Value are combined into this equation.  ZooKeeper is designed as a high read, high throughput system for small keys.  It is not designed as […]

Hudson job running on Slave continually fails

I ran into an issue where we had all jobs in particular failing on a certain slave.  Let’s just assume a simple Hudson master/slave environment of 1 Hudson Master and 2 Hudson slaves Slave A and Slave B. The boxes are the exact same hardware specs.  Same configuration, etc.  Jobs are created on the master […]

AccessDenied error on an asset in Amazon S3 Storage

Have you ever seen this error while interacting with your assests through the Amazon S3 storage? <Error> <Code>AccessDenied</Code> <Message>AccessDenied</Message> <RequestId>B9EE5C8B93FF7210</RequestId> <HostId>DqW6EksDls0seRl+TscPrIMd8MtX14GVYwk3Sb5erKN+nyc5UXV5lAEYBZWFkjL7</HostId> </Error> Well – I sure have… a lot… This error can mean a few things… but more then likely it is one of two most probably causes. The file does not exist The file […]

How do you monitor Apache ZooKeeper Connection counts?

What is the best way to monitor the number of connections a ZooKeeper server is servicing? Well – I think the correct answer to that depends on what type of brain you are.  For example if you are a programmer – you will probably be more interested in the number of watches or subscriptions on […]