ywcb00 opened a new pull request, #1647: URL: https://github.com/apache/systemds/pull/1647
Hi, This PR changes the local variable map back to a _ConcurrentHashMap_ in order to allow for simultaneously modification and iteration of the map. Without a _ConcurrentHashMap_, some algorithms might throw a _ConcurrentModificationException_ because the coordinator does not wait for the worker's result and triggers a new federated instruction in the meanwhile. Therefore, the worker iterates the local variable map when performing an '_rmvar_' instruction, and creates new entries in the local variable map at the same time, resulting in a _ConcurrentModificationException_. Thanks to @kev-inn for finding this issue. Another approach to resolve this problem would be to create a queue of federated requests for every coordinator+threadid pair and process the requests of the queue sequentially. Thanks for review :) -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
