@Sami Ahmad An easy way to return NiFi to a blank canvas, is to simply stop NiFi and remove the flow.xml.gz file from the NiFi's conf directory. When you restart your NiFi a new blank flow.xml.gz file will be generated. Any FlowFiles that had existed in the deleted flow will be purged from NiFi when it is started. Alternatively: The error you are seeing is occurring because you are inside a NiFi process group and trying to delete all the components; however, NiFi has detected that there are connections attached to that process group from the process group one level up. NiFi will not allow those components to be removed until there feeding connections are removed first. If you return to the root/top level of your NiFi dataflow you can select the connection entering and existing a process group and delete them. Once they have been deleted, you can select the process group itself and delete it. This will in turn delete all components inside that process group. The deletion of connections will only be allowed if there is no queued FlowFiles in that connection. If there is queued FlowFiles, the FlowFiles must be purged before the connection can be deleted. Matt ... View more

@Sami Ahmad I am not saying it will not work as is; however, without a defined path forward from those two output ports the data will just Queue. Looking at your screenshot, it does look like the dataflow is producing FlowFiles. If you look at the stats on the process groups "log Generator" and "Data Enrichment" you will see data being produced and queued. The problem is that none of the components inside "Data Enrichment" are running. If you double click on the "Data Enrichment" process group, you will be taken inside of it. There you will see the stopped components, the invalid components, and the ~20,000 queued FlowFiles. You will need to start all the valid stopped components in this process group to get your data flowing all the way to your two putHDFS processors outside this process group. There are two output ports in this "Data Enrichment" process group that are invalid. They are not necessary for this tutorial to work. I suggest you stop the "Filter WARN" and "Filter INFO" processors and delete the connections feeding these invalid output ports. If you have already run this flow and data exists queued on these connections you wish to delete, you will need to right click on the connection and select "Empty queue" before you will be able to delete it. These example were not put out by Apache. I will try to find the correct person who wrote this tutorial and see if i can get them to update it. Thanks, Matt ... View more

@David DN NiFi 1.x (HDF 2.x) versions have gone through a major framework upgrade/change. A multi-tenancy approach has been added that allows users to control the access of users down to the component level. As part of this change, the way the initial admin user is added has changed. In previous NiFi 0.x (HDF 1.x) versions, this was simply done by adding the DN of your first admin user to the authorized-users.xml file. In NiFi 1.x (HDF 2.x) versions you need to set that user DN in the following property in the authorizers.xml file: <property name="Initial Admin Identity"></property> For those who previously worked with NiFi 0.x (HDF 1.x) versions, you can use an old authorized-users.xml file to seed the new NiFi version's user authorization by setting this property in the same file: <property name="Legacy Authorized Users File"></property> NiFi 1.x (HDF 2.x) version no longer provide new users the ability to "request access". An Admin will need to manually added each users and assign them component level access through the UI. adding new users is done through the users UI found in the hamburger menu in the upper right corner of the UI. (Remember this can only be done once initial admin as given access as described above). From the Users UI, select the add user icon in the upper right corner : The above UI will appear to add your new users. Supply your kerberos, LDAP, or certificate DN and click "OK" Now that you have added a user you need grant them component level access back on the main NiFi UI. Select the component you which to control access to. In the below example we will select the root canvas: A new "Access Policies" Ui will appear where you need select the access policy you want to add the user to from the pull down menu: Once you select Policy, click on the add user icon in the upper right to grant access to one of the users added earlier. Thanks, Matt ... View more