Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
added driven examples to the Impatient series
- Loading branch information
1 parent
5dca4dd
commit d7384fe
Showing
22 changed files
with
297 additions
and
76 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Original file line number | Diff line number | Diff line change |
---|---|---|
@@ -0,0 +1,31 @@ | ||
Let's understand better how to read the timeline view. To do that, let's go deeper | ||
into understanding the different states for the Cascading application. | ||
|
||
image:cascading-state.png[] | ||
|
||
As the Cascading framework composes the Flows, they enter the "Pending" state. Since | ||
Flows within a Casacade can have dependencies, the Flows stay in the "Pending" state | ||
until all the dependencies predicating its execution have successfully completed. | ||
|
||
Similary, as the query planner maps the assembly of steps into Mappers and Reducers (or other | ||
execution primitives associated with the underlying fabric), they now enter the "Submitted" | ||
state waiting the work unit to be executed, at which time they enter the "Running" state | ||
|
||
Measuring how much time the application, flow, or a Cascading step spends in a particular state | ||
can give valuable insights about how to improve the performance of your application. | ||
|
||
For example, a large time interval between the submitted and running time can allude to | ||
concurrency issues in running MapReduce jobs, and suggesting that increasing the number | ||
of mapper or reducer slots can significantly improve the application performance. | ||
|
||
Similarly, if the application spends a large proportion of its total run time in | ||
pending state, it may be cause to review your application architecture and see how | ||
some dependencies between the Flows be eliminated. | ||
|
||
You can visualize this information related to latencies for each state from two places. | ||
Hover your mouse over the timelime bars, and you can see the state associated with | ||
each color band. For a more detailed and an analytical view, select "Add Columns", and select | ||
the following counters: "Pending Time", "Start Time", "Submit Time", "Run Time", "Finished Time" | ||
|
||
Now with these detailed insights, you are ready to take your application tuning to the | ||
next level! |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.