@Dmitry  Trying to fully understand your use case here... You have 1 to many FlowFile where you want to merge the content of each of those FlowFiles in to a single FlowFile if all those FlowFile have an attribute "manager_name" with the same value? If so, the MergeContent [1] or MergeRecord [2] processors could do that for you.  You would set the "Correlation Attribute Name" property in those processors the place incoming FlowFiles in to bins based on unique values set for "manager_name" on each incoming FlowFile.  Those bins are then merged based on criteria set in other properties on the processor. The merged output FlowFile will have several new attribute written to it.  One of those new attributes is "merge.count" which will contain the count of the number fo input FlowFiles that were merged.   You could use an UpdateAttribute processor to read the value from "merge.count" and "manager_name", then assign those to other attribute named "total" and "general key" is those attribute names are specifically needed. [1] http://nifi.apache.org/docs/nifi-docs/components/org.apache.nifi/nifi-standard-nar/1.13.2/org.apache.nifi.processors.standard.MergeContent/index.html [2] http://nifi.apache.org/docs/nifi-docs/components/org.apache.nifi/nifi-standard-nar/1.13.2/org.apache.nifi.processors.standard.MergeRecord/index.html   If you found this information helped with you question, please take a moment to login and click accept on this solution. Matt ... View more

@Justee  So with NiFi, there is a UI, but you need to make sure there is a route to the host (where you are laughing your browser) and target: <hostname/IP>:<port>  If your NiFi in startup is binding to private network interface or only the loopback IP address, you would most likely be unable to reach those IPs from your client machine on a public network. From your client machine, can you ping that "<hostname/IP>"? Does the server where your NiFi is running have multiple network interfaces for perhaps a public and a private network?  Did you try changing the IP that NiFi binds to in nifi.properties file: nifi.web.http.host= Did you try to tell your NiFi to bind to multiple network interfaces in the nifi.properties file if they exist in that server?  For example: nifi.web.http.network.interface.eth0=eth0 nifi.web.http.network.interface.eth1=eth1 Your servers network interfaces may be different then above example. If you found this solution helpful, please take a moment to login in and click accept on all solutions that helped you. Thanks, Matt ... View more

@pherschmann    The "nifi is running but not responding to ping requests" is not referring to ability to ping the host. When NiFi is started, you are starting the NiFi bootstrap process. This bootstrap process then starts a child NiFi process which is what runs the main NiFi that you interact with.  When you run the status command, it us asking the bootstrap process to return the status of that child process.  It is telling you that it sees that the PID for that child process still exists so reports it is running, but when it tries to get a response from that child process it fails and logs that the status ping got no response. This almost always is the result of some resource contention within NiFi.  The NiFi process may have been going through Java Garbage Collection (GC) at the time you ran the status command. (all GC is stop-the-world event, so JVM will not respond to anything else), or thread usage (CPU consumption) was high at the time, etc... If you see this allot or are seeing node disconnection or UI stability issues, you may want to start monitoring resources on the host, or maybe enable GC logging in your NiFi to see if the service is spending a lot of time doing GC.  Increasing heap allocated to NiFi or making dataflow design changes to reduce the heap memory footprint of your current dataflow(s) design would help there. Hope you found this information helpful. If so, please take a moment to login and click accept on this solution, Matt ... View more

@Arash  A FlowFile consists of to parts: - FlowFile content - Content resides on disk in the content repository and not in heap memory.  Some components used may need to load content in to memory to perform the function of that component. - FlowFile Attributes/metadata - FlowFiles actively queued in a connection will have their attributes/metadata held in heap memory.  Swapping is the only mechanism that can move this FlowFile metadata/attribute data out of heap to swap on disk. It is important to remember that MiNiFi will only start swapping FlowFiles to disk once the swap threshold  per connection reaches the configured value(default 20,000).  Swap files are created in batches of 10,000.  So in a smoothly running flow there should be very little, if any, swapping of FlowFile attributes/metadata happening.  This should only be happening at times of data bursts. To keep heap usage down, limit the size of your connection queue backpressure object threshold.  The default is 10000 which means a connection would never accumulate enough FlowFiles to trigger a swap file anyway normally (backpressure is a soft limit, so if a source processor is allowed to execute because the downstream connection is not applying backpressure yet and that source processor execution results in 30,000 FlowFiles being created, then all 30,000 are placed on downstream connection which would result in swap files being created). When you are building your dataflow via NiFi that you will use on your MiNiFi agent, be mindful of above and and look at the embedded documentation for the components you will be using in that dataflow.  The embedded docs include resource consideration section under each component if there are known impacts on heap memory or cpu.  Processors that merge or split FlowFiles commonly used can have an impact on heap memory if not configured wisely. Hope this helps remove some concern and provide useful insight. If you found this helpful, please take a moment to login and click accept on this solution. Matt ... View more