Resolve job hang at record joiner in Spectrum


Flow become unresponsive after processing some records without reporting any error or creating any hang dump. Flow execution does not complete
even after several days.


This could occurs when a single path is first branched using Conditional Router stage and then joined back using the Record Joiner stage. In this situation Record Joiner is busy sorting data from each input flow and goes unresponsive.

The Record Joiner stage works best when the two independent streams are joined to generate the consolidated output. If the flow looks like the following, it will not result in a hang.
User-added image
In such a flow, the Record Joiner will not hang no matter how many stages exist between Read from File stage and Record Joiner stage.
User-added image
The flow hang issue occurs when a single path is first branched using Broadcaster / Conditional Router stage and then joined back using Record Joiner stage.

User-added image


UPDATED: August 30, 2017

Flows that involve branching and joining same input data must be avoided as much as possible. If the branching and joining cannot be avoided, input data should be sorted right before Record Joiner stage. This is to ensure that the Record Joiner receives data on all its input ports at a similar rate to avoid unresponsiveness.

If there are multiple stages happening between the branching (Conditional Router / Broadcaster) and Record Joiner, we need to push Sorter stage to be closer to Record Joiner stage to avoid flow being unresponsive.

1. Place 'Sorter' stage on all input flows before 'Record Joiner' stages
2. Sort fields in 'Sorter' stage should be same as in 'Record Joiner' stage.
3. Select 'data is already sorted' option in 'Record Joiner' stage.
a. 'Data from left port is sorted' should be checked
b. Modify 'Join Definitions' and ensure 'Data from right port is sorted' is also checked.

Note: Ensure that the conditions in the 'Conditional Router' stage are intact while making the changes.

User-added image


Environment Details

Product Feature: Performance



  • No Downloads