How to notify from publisher to subscriber before stopping publishing data.
How to know from subscriber's end that publisher stopped the publishing data. in my subscriber code i am performing clean up operations and would like to know if publisher stopped publishing the data.Here i am publishing the data based on topic not a service so how to create link or notification between publisher and subscriber in case publisher stopped publishing data. Usually if publisher node is not publishing the data then subscriber node callback itself won't be called.
Can you confirm whether you are actually trying to determine whether publishers are still on-line (ie: not terminated), instead of just publishing messages?
if publisher are alive and publishing the data , in this case i don't want any bookkeeping.. i just wanted to know from subscriber's end if publisher got stopped due to crash or ctrl+c operation and not publishing anything.