Interface ExternalSynchronization
- All Superinterfaces:
Serializable
- All Known Implementing Classes:
HDFSSynchronization
Provides mechanism for acquiring locks related to the job. Serves as source of unique events
among the job.
-
Method Summary
Modifier and TypeMethodDescriptionorg.apache.hadoop.mapreduce.TaskAttemptID
acquireTaskAttemptIdLock
(org.apache.hadoop.conf.Configuration conf, int taskId) Creates uniqueTaskAttemptID
for given taskId.org.apache.hadoop.mapreduce.TaskID
acquireTaskIdLock
(org.apache.hadoop.conf.Configuration conf) CreatesTaskID
with unique id among given job.void
releaseJobIdLock
(org.apache.hadoop.conf.Configuration conf) Deletes lock ids bounded with given job if any exists.boolean
tryAcquireJobLock
(org.apache.hadoop.conf.Configuration conf) Tries to acquire lock for given job.
-
Method Details
-
tryAcquireJobLock
boolean tryAcquireJobLock(org.apache.hadoop.conf.Configuration conf) Tries to acquire lock for given job.- Parameters:
conf
- configuration bounded with given job.- Returns:
true
if the lock was acquired,false
otherwise.
-
releaseJobIdLock
void releaseJobIdLock(org.apache.hadoop.conf.Configuration conf) Deletes lock ids bounded with given job if any exists.- Parameters:
conf
- hadoop configuration of given job.
-
acquireTaskIdLock
org.apache.hadoop.mapreduce.TaskID acquireTaskIdLock(org.apache.hadoop.conf.Configuration conf) CreatesTaskID
with unique id among given job.- Parameters:
conf
- hadoop configuration of given job.- Returns:
TaskID
with unique id among given job.
-
acquireTaskAttemptIdLock
org.apache.hadoop.mapreduce.TaskAttemptID acquireTaskAttemptIdLock(org.apache.hadoop.conf.Configuration conf, int taskId) Creates uniqueTaskAttemptID
for given taskId.- Parameters:
conf
- configuration of given task and jobtaskId
- id of the task- Returns:
- Unique
TaskAttemptID
for given taskId.
-