FileCommitProtocol
Related Docs:
object FileCommitProtocol
| package io
Aborts a job after the writes fail.
Aborts a job after the writes fail. Must be called on the driver.
Calling this function is a best-effort attempt, because it is possible that the driver just crashes (or killed) before it can call abort.
Aborts a task after the writes have failed.
Aborts a task after the writes have failed. Must be called on the executors when running tasks.
Calling this function is a best-effort attempt, because it is possible that the executor just crashes (or killed) before it can call abort.
Commits a job after the writes succeed.
Commits a job after the writes succeed. Must be called on the driver.
Commits a task after the writes succeed.
Commits a task after the writes succeed. Must be called on the executors when running tasks.
Notifies the commit protocol to add a new file, and gets back the full path that should be used.
Notifies the commit protocol to add a new file, and gets back the full path that should be used. Must be called on the executors when running tasks.
Note that the returned temp file may have an arbitrary path. The commit protocol only promises that the file will be at the location specified by the arguments after job commit.
A full file path consists of the following parts:
The "dir" parameter specifies 2, and "ext" parameter specifies both 4 and 5, and the rest are left to the commit protocol implementation to decide.
Important: it is the caller's responsibility to add uniquely identifying content to "ext" if a task is going to write out multiple files to the same dir. The file commit protocol only guarantees that files written by different tasks will not conflict.
Similar to newTaskTempFile(), but allows files to committed to an absolute output location.
Similar to newTaskTempFile(), but allows files to committed to an absolute output location. Depending on the implementation, there may be weaker guarantees around adding files this way.
Important: it is the caller's responsibility to add uniquely identifying content to "ext" if a task is going to write out multiple files to the same dir. The file commit protocol only guarantees that files written by different tasks will not conflict.
Setups up a job.
Setups up a job. Must be called on the driver before any other methods can be invoked.
Sets up a task within a job.
Sets up a task within a job. Must be called before any other task related methods can be invoked.
An interface to define how a single Spark job commits its outputs. Two notes:
1. Implementations must be serializable, as the committer instance instantiated on the driver will be used for tasks on executors. 2. Implementations should have a constructor with either 2 or 3 arguments: (jobId: String, path: String) or (jobId: String, path: String, isAppend: Boolean). 3. A committer should not be reused across multiple Spark jobs.
The proper call sequence is:
1. Driver calls setupJob. 2. As part of each task's execution, executor calls setupTask and then commitTask (or abortTask if task failed). 3. When all necessary tasks completed successfully, the driver calls commitJob. If the job failed to execute (e.g. too many failed tasks), the job should call abortJob.