Environment NiFi 2.7.2, 3-node cluster (3EC2 - 3ASG) ZooKeeper: 3-node ensemble (ECS) NiFi Registry (ECS) AWS Step Functions for scheduled stop/start (cost optimization) Problem After an overnight shutdown/startup, the cluster becomes unstable: Nodes rapidly flap: CONNECTED → DISCONNECTED → CONNECTING (every 2-3 seconds). Error: "Have not received heartbeat from node". Critical: Disconnected node logs show NO errors/warnings - node appears healthy while coordinator reports it as disconnected. Root Cause Parallel startup via Step Function Map state causes: NiFi nodes start before the ZooKeeper quorum forms All 3 nodes start simultaneously → chaotic coordinator election Resolution Deleted flow.xml.gz on disconnected nodes → restart → nodes rejoined successfully Proposed Solution Sequential startup with proper wait times:   1. ZK1 → 60s → ZK2 → 60s → ZK3 → 120s (quorum)2. NiFi Registry → 90s3. Node 1 → 180s → Node 2 → 120s → Node 3 → 120s Sequential shutdown (reverse order) Questions Official guidance on startup sequencing for multi-node clusters with external ZooKeeper? Should ZooKeeper state be cleared during scheduled shutdowns? Why don't disconnected node logs show any issues? Node appears unaware of disconnection. Recommended wait times between service starts? Best practices for scheduled start/stop on auto-scaling infrastructure? Setup Details 32GB RAM, 20GB heap, G1GC Java 21 Amazon Corretto Time sync verified (chrony < 1μs drift) Network healthy, no packet loss Has anyone implemented similar scheduled automation for NiFi clusters? Any guidance appreciated! ... View more

My NiFi (1.24) is running using the AWS ECS, 3 nodes, and connected via ALB as a cluster. So, my case is how to make sure that the opened node by the users/developers is the primary one (When accessing the ALB URL). This is to avoid allowing them to apply their changes over the non-primary one, as almost with every new flow update by the developer, I am getting one of my nodes disconnected and unable to sync with the primary one!   ... View more

I am running 3 nifi nodes using AWS ECS, while the development team is working over the nifi console, we are getting an error related to the unable to sync. So the node is being disconnected. My mind is this issue is happening due to that the changes are not being made over the primary node. How can I enforce that the changes are applied directly to the primary node to avoid this issue? Can any one help? ... View more