Book Image

Apache ZooKeeper Essentials

By : Haloi
Book Image

Apache ZooKeeper Essentials

By: Haloi

Overview of this book

Whether you are a novice to ZooKeeper or already have some experience, you will be able to master the concepts of ZooKeeper and its usage with ease. This book assumes you to have some prior knowledge of distributed systems and high-level programming knowledge of C, Java, or Python, but no experience with Apache ZooKeeper is required.
Table of Contents (9 chapters)
4
4. Performing Common Distributed System Tasks
8
Index

The ZooKeeper stat structure

Every znode in ZooKeeper's namespace has a stat structure associated with it, which is analogous to the stat structure of files in a Unix/Linux filesystem. The fields in the stat structure of a znode are shown as follows with their respective meanings:

  • cZxid: This is the transaction ID of the change that caused this znode to be created.
  • mZxid: This is the transaction ID of the change that last modified this znode.
  • pZxid: This is the transaction ID for a znode change that pertains to adding or removing children.
  • ctime: This denotes the creation time of a znode in milliseconds from epoch.
  • mtime: This denotes the last modification time of a znode in milliseconds from epoch.
  • dataVersion: This denotes the number of changes made to the data of this znode.
  • cversion: This denotes the number of changes made to the children of this znode.
  • aclVersion: This denotes the number of changes made to the ACL of this znode.
  • ephemeralOwner: This is the session ID of the znode&apos...