hui730 commented on PR #43621: URL: https://github.com/apache/spark/pull/43621#issuecomment-1790095897
> Each task has a reference to a broadcast'ed task binary `Array[Byte]` - not the object. This `Array[Byte]` is pulled to each executor once - and for each subsequent task, this `Array[Byte]` is reused to deserialize and create a new task closure. So essentially we are trying to save on a jvm local deserialization cost. > > Explicit use of broadcast variables is documented to be read only - but with task closures, I would be very reluctant to assume this behavior. If the instance is reused, task closures can start having side effects on other tasks in the same executor. Okay, I get what you mean. Especially in Hadoop. My plan is to create a new binary from executor binary，use System.arraycopy(). How do you like it， sir？:) -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
