Phase verses Checkpoint

Difference between a phase and checkpoint as far as i know it something related with how temporary files containing the data landed to disk is handled.
that is phases are used to break up a graph so that it does not use up all the memory , it reduce the no of component running in parallel hence improves the performances (used for performance fine tuning, by managing the resource in perfect manner)

Check points are used for the purpose of recovery.

Questions by sixto.dsilva   answers by sixto.dsilva

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chandu9739

  • Sep 6th, 2008
 

Phase does not create temp files in the host directory whereas checkpoint creates .temp file in host directory of the operating system.

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The major difference between these to is that phasing deletes the intermediate files made at the end of each phase, as soon as it enters the next phase. On the other hand, what checkpointing does is...it stores these intermediate files till the end of the graph. Thus we can easily use the intermediate file to restart the process from where it failed. But this cannot be done in case of phasing.

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Phases are used in case to use the resources such as memory, disk space, and CPU cycles for the most demanding part of the job.Say, we have memory consuming components in the straight flow and the data in flow is in millions,we can separate the process out in one phase so as the cpu allocation is more for the process to consume less time for the whole process to get over.

In contrary,Checkpoints are like save points while we play a PC game.These are required if we need to run the graph from the saved last phase recovery file(phase break checkpoint) if it fails unexpectedly.

Use of phase breaks which includes the checkpoints would degrade the performance but ensures save point run.Toggling Checkpoints could be helpful for removing checkpoints from phase break.

Abhisek B.
fresh as dew! 

Above GDE version 1.8 checkpoint is automatic.

Phasing is when you design the graph it should not have more than 20 components. In that particular phase the component in that phase will alone run.

Check point is also associated with phasing. We can see a blue color block filled around the phasing that is check point. When the execution of the graph is interrupted and it has fetched 10,000 record. when you re-run the graph, it will ask for option restart or continue. So checkpoint is used to run the graph from where its interrupted.

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Phase is breaking the graph into different block. It create some temp file while running and deletes it once the completion is done.

Checkpoint is used for recovery purpose. when the graph is interrupted, instead of rerunning the graph from the start. the excution starts from the stop where it is stopeed

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Bhanu

  • Mar 25th, 2014
 

Phase:

Phase is a stage of graph that runs to completion before the start of the next phase.
Phase creates the intermediate/temporary file and delete it regardless of knowing whether the graph runs successfully or not.Phase is used for performance tuning.It is useful to avoid deadlocking.The boundary between the two blocks is known as phase break.

Checkpoint
Checkpoint creates the temporary files but donot delete the files till the end of the execution of graph.Hence whenever we can rerun the graph from where the graph got interrupted.
Checkpoint is bas

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preethi

  • Oct 16th, 2016
 

The component immediately before the phase break writes the data into a temporary file in the layout of the component after the phase break

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Mayank

  • Dec 28th, 2016
 

Short answer
The essential differences between a phase and a checkpoint are their purpose and how the temporary files containing the data landed to disk are handled:
Phases are used to break up a graph into blocks for performance tuning.
Checkpoints are used for recovery.
Details
The following descriptions clarify the differences between phases and checkpoints:
Phase — The primary purpose of phasing is performance tuning by managing resources. Phasing limits the number of simultaneous processes by breaking up a graph into different pieces, only one of which is running at any given time. One common use of phasing is to avoid deadlocks. The temporary files created by phasing are deleted at the end of the phase, regardless of whether the run was successful.
Checkpoint — The main aim of checkpoints is to provide the means to restart a failed graph from some intermediate state. When a graph with checkpoints fails, the temporary files from the last successful checkpoint are retained so you can restart the graph from this point in the event of a failure. Only as each new checkpoint is completed successfully are the temporary files corresponding to the previous checkpoint deleted.

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