@anil35759    If you create a NiFi template that includes a NiFi processor that references a controller service, that controller service will be included in the generated template.  So if you import and instantiate that template on to the canvas of another NiFi, the controller service will be added as well and be associated with the processor instantiate from that same template. https://nifi.apache.org/docs/nifi-docs/html/user-guide.html#templates   So I am not clear on why you need to import the controller service separately via the toolkit.   Controller services are not mapped to processors.  The association happens from the processor side.   The processor is mapped to a specific controller service via the controller services assigned uuid. Keep in mind that anything you can do within the NiFi Ui can also be accomplished using NiFi rest-api endpoints.  Using your browsers developer tools to capture the requests as you make them through the NiFi UI is a great way to learn how to interact with NiFi rest-api endpoints.  The rest-api endpoints specific to your NiFi release version can be found under help within your install. Here are the Apache NiFi rest-api docs for the latest Apache release version: https://nifi.apache.org/docs/nifi-docs/rest-api/index.html Essentially what you need to do here is to update the processor configuration to reference the UUID of whichever controller service you want it to use. curl 'http://<nifi-hostname>:<nifi-port>/nifi-api/processors/b10fd083-0170-1000-0000-00007f7c905f' -X PUT --data-binary '{"component":{"id":"b10fd083-0170-1000-0000-00007f7c905f","name":"ExecuteSQL","config":{"concurrentlySchedulableTaskCount":"1","schedulingPeriod":"0 sec","executionNode":"ALL","penaltyDuration":"30 sec","yieldDuration":"1 sec","bulletinLevel":"WARN","schedulingStrategy":"TIMER_DRIVEN","comments":"","autoTerminatedRelationships":[],"properties":{"Database Connection Pooling Service":"e60cb24c-95c5-3a97-bcb9-9e537006317d"}},"state":"STOPPED"},"revision":{"clientId":"affea95c-0170-1000-988b-73bf756785b3","version":2},"disconnectedNodeAcknowledged":false}   So you'll notice from above example, I am updating a processor's (ExecuteSQL) configuration so that the Database Connection Pooling Service is mapped to the UUID of my DBCPConnectionPool controller service's uuid (e60cb24c-95c5-3a97-bcb9-9e537006317d).   Note:  The "clientId" string can be anything.    Hope this helps, Matt   ... View more

@sfishman  In the "Replacement value" configuration property just hold the <shift> key and hit enter instead of using "\n". Here is example of what you would see: This will create the line return you are looking for.   Hope this helps, Matt ... View more

@domR    I see no issues with using a publish and consume design for triggering follow on flows. That provide a slightly more robust setup than using the postHTTP to ListenHTTP example I provided since any NiFi node can consume the trigger file. When using Kafka you will want to make sure you have the same number of partitions as you have consumer in the same consumer group.  When you add a consumeKafka processor to the NiFi canvas it is really being added to every node in your cluster and is configured the same on every node. Let's assume you have a 3 node NiFi cluster, that means you have at a minimum 3 consumers in that consumer group so your Kafka topic should have 3 partitions; otherwise, you may see a lot of rebalancing happen.  To improve performance even more you can increase the concurrent task on your consumeKafka processor.  With a 3 node NiFi cluster and a consumeKafka configured with 2 concurrent tasks, you now have 6 total consumers in the consumer group; therefore, your Kafka topic should have 6 partitions.   If a NiFi node goes down Kafka will assign multiple partitions to the same consumer, so no need to worry about messages not being consumed. Hope this information was useful in finding a solution, Matt ... View more

@varun_rathinam    Can you please elaborate on "processor drop the file and join with new files"? And also "content_repository backup i limit"?  <-- Are you referring to the "nifi.content.repository.archive.max.retention.period" and "nifi.content.repository.archive.max.usage.percentage" configuration settings in the nifi.properties file? Also sharing a screenshot of your current MergeContent processor's configuration along with more details around your use case.  What result are you seeing now and what is the desired result? The MergeContent processor takes multiple FlowFiles from same NiFi node and merges the content of those FlowFiles based on the processor's configuration in to one or more new FlowFile's per node.  The processor cannot merge FlowFiles residing on different NiFi nodes in an NiFi cluster into one FlowFile.   FlowFiles from the inbound connection queue are allocated to bins based on the following configuration properties: Correlation Attribute Name  <-- (Optional) when used, only FlowFile with same value in the configured FlowFile attribute will be placed in same bin. Maximum Number of Entries  <-- Maximum number of FlowFiles that can be allocated to a single bin before a new bin is used. Maximum Group Size  <-- (Optional) Maximum cumulative size of the content that can be allocated to a bin   When a "bin" is eligible to be merged is controlled by these configuration properties: Minimum Number of Entries  <-- If at end of thread execution (after all FlowFiles from inbound connection have been allocated to one or more bins) the number of FlowFiles allocated to a bin meets this min and meets configured min group size, the FlowFiles in that bin will be merged. Minimum Group Size  <-- Same as above Max Bin Age  <-- A bin that has not reached or exceeded both above min values will merge once the bin has had FlowFiles in it for this amount of time  Maximum number of Bins  <-- If FlowFile have been allocated to every bin and another bin is needed, the oldest bin will be forced to merge to free a bin.   It is possible that one or both min values are never reached if a Max bin setting is reached first.  This means that because of max additional FlowFiles can not be allocated to that bin and the only setting that will force that bin to merge is "Max Bin Age" or you run out of free bins. As far as bin Max values, NiFi really does not care about content size as it streams the merged FlowFiles content in to a new FlowFile and does not hold that content in memory.  NiFi can experience Out OF Memory (OOM) conditions if the number of FlowFiles Max is set too high since all the attributes for every FlowFile currently allocated to bin(s) is held in heap memory.  NiFi's allocated heap memory is set in the nifi.properties configuration file. So a Max number of entries should be limited to 10000 (but this varies based on memory availability and number and size of attributes on your FlowFiles.  You can use multiple MergeContent processors in series (one after another) to merge multiple merged FlowFiles in to even larger merged FlowFiles if desired.   Hope this helps with understanding the MergeContent processor, Matt ... View more

@Umakanth    The API is exposed out of the box, it is not something you need to enable. Every action you take while performing actions within the UI makes a call to the NiFi rest-api. When learning how to use the rest-api calls, you may find using the developer tools in your browser helpful. Open the developer tools  while you are accessing your NiFi UI.  Then perform some action and you will see those requests being made by your browser to NiFi.  In the below example (Using Chrome browser developer tools), I opened NiFi's summary UI from the global menu in the upper right corner of the UI: You'll notice that several requests were made.  I can write click on any one of those request and select "Copy as cURL" to copy the full request to the system clipboard. I can then paste the request in a terminal window and see what the rest-api call returns.  You will notice that the curl command that is copied will have numerous additional headers (-H) that are not always necessary depending on the rest-api endpoint being used.  Example: curl 'http://<nifi-hostname>:<nifi-port>/nifi-api/flow/process-groups/root/status?recursive=true' Of course you will need to parse the rest-api returns yourself to extract in many cases the specific details/stats you want to monitor. Hope this helps, Matt ... View more