@Petr_Simik    No matter which processor you are looking at the stats presented all tell you the same information: In  <-- Tells you how many FlowFile were processed from one or more inbound connections over the last rolling 5 minute window.  With this processor you have it configured the "wait mode" to leave the FlowFile on the inbound connection.  So the processor is constantly looking at the file over and over again until the configured expiration time has elapsed. Read/Write. <-- Tells you how much FlowFile content was read from or written to the NiFi content repository (helps user identify processors that may be disk I/O heavy)   Out. <-- Tells you how many FlowFiles have been released to an outbound connection over the last rolling 5 minute window.  Here you see a number that reflects only those flowfiles that expired and where sent to your outbound expired connection. Tasks/Time. <-- Tells you how many threads this processor completed execution over the last rolling 5 minutes and the total cumulative time those threads consumed from the CPU.   (helps user identify what processors consume lots of CPU time) So the stats you are seeing are not surprising. While this processor works for your use case i guess, it has overhead needing to connect to a distributed map cache on every execution against an inbound FlowFile.  If your intent is only to delay a FlowFile for 1 second before it proceeds down the flow path, a better solution may be to just use an updateAttribute processor that creates an attribute with current time and RouteOnAttribute processor that checks to see if that recorded time plus 1000 ms is less than current time.  Then loop that check until it is not. Hope this helps, Matt ... View more

@Faerballert  Perhaps you clone your flowfile before the mergeContent processors. So whichever relationship you are connecting to your current mergeContent, you drag a second connection containing that same relationship to a parallel notification flow. Down this parallel flow path you use a replaceText processor to replace the content with the value from the attribute you want to merge.  Then you use a mergeContent processor on this path to merge these files using a "," as your delimiter.   Then from this mergeContent you do you notification. You may also want to open an Apache Jira with your use case and desired improvement for the existing mergeContent.  The more details the better. Hope this helps, Matt ... View more