Struct zookeeper::Stat
[−]
[src]
pub struct Stat { pub czxid: i64, pub mzxid: i64, pub ctime: i64, pub mtime: i64, pub version: i32, pub cversion: i32, pub aversion: i32, pub ephemeral_owner: i64, pub data_length: i32, pub num_children: i32, pub pzxid: i64, }
Statistics about a znode, similar to the UNIX stat
structure.
Time in ZooKeeper
The concept of time is tricky in distributed systems. ZooKeeper keeps track of time in a number of ways.
- zxid: Every change to a ZooKeeper cluster receives a stamp in the form of a zxid (ZooKeeper Transaction ID). This exposes the total ordering of all changes to ZooKeeper. Each change will have a unique zxid -- if zxid:a is smaller than zxid:b, then the associated change to zxid:a happened before zxid:b.
- Version Numbers: Every change to a znode will cause an increase to one of the version numbers of that node.
- Clock Time: ZooKeeper does not use clock time to make decisions, but it uses it to put
timestamps into the
Stat
structure.
Fields
czxid: i64
The transaction ID that created the znode.
mzxid: i64
The last transaction that modified the znode.
ctime: i64
Milliseconds since epoch when the znode was created.
mtime: i64
Milliseconds since epoch when the znode was last modified.
version: i32
The number of changes to the data of the znode.
cversion: i32
The number of changes to the children of the znode.
aversion: i32
The number of changes to the ACL of the znode.
ephemeral_owner: i64
The session ID of the owner of this znode, if it is an ephemeral entry.
data_length: i32
The length of the data field of the znode.
num_children: i32
The number of children this znode has.
pzxid: i64
The transaction ID that last modified the children of the znode.
Methods
impl Stat
[src]
fn is_ephemeral(&self) -> bool
Is the znode an ephemeral entry?