Pulsar Max Consumers: Configure Topic Limits
Pulsar's "max consumers" setting on a topic isn't about limiting how many clients can read from a topic, but how many can be actively connected and cons.
Pulsar Articles
80 articles
Pulsar Message Deduplication: Exactly-Once Producers
Pulsar's "exactly-once" producer semantics don't actually guarantee exactly-once delivery; they guarantee exactly-once processing by the producer itself.
Pulsar Retention and Backlog: Configure Message Limits
Pulsar retention and backlog limits are a bit like a leaky faucet, you can turn it off, but if you don't understand why it's dripping, you'll be back to.
Pulsar Monitoring: Prometheus and Grafana Dashboards
Pulsar monitoring with Prometheus and Grafana is less about collecting metrics and more about understanding the emergent behavior of a distributed syste.
Pulsar Multi-Tenancy: Tenants and Namespace Isolation
Pulsar's multi-tenancy isn't just about grouping topics; it's about fundamentally isolating resources to prevent noisy neighbors and enforce strict acce.
Pulsar Namespace Policies: Configure Per-Namespace Rules
Pulsar namespaces don't just group topics; they're the primary mechanism for enforcing granular operational policies across sets of topics.
Pulsar Non-Persistent Topics: Low-Latency Use Cases
Pulsar's non-persistent topics are designed for use cases where data durability isn't the primary concern, but rather extreme low latency and high throu.
Pulsar Oxia: Migrate from ZooKeeper Metadata Store
Migrating Pulsar from ZooKeeper to the native BookKeeper metadata store Oxia doesn't just change where your metadata lives; it fundamentally alters how .
Pulsar Perf Tool: Benchmark Throughput and Latency
Pulsar's performance tuning is less about tweaking knobs and more about understanding how your application's access patterns interact with Pulsar's tier.
Pulsar Topic Metrics: Expose Prometheus Per-Topic Data
Pulsar exposes per-topic metrics through Prometheus, but the default configuration often hides this granular data, leading people to believe it's not av.
Pulsar Admin CLI: Manage Clusters and Topics
Pulsar clusters are not just arbitrary groupings of brokers; they are foundational units of isolation and administration that dictate how data flows and.
Pulsar Reader API: Replay Messages from Any Offset
Pulsar's Reader API, designed for sequential consumption, can actually jump back and replay messages from any arbitrary offset within a topic partition,.
Pulsar Replication Lag: Monitor Cross-Cluster Latency
Pulsar replication lag isn't just about how long it takes data to get from A to B; it's a symptom of the underlying network and Pulsar broker health tha.
Pulsar Schema Registry: Avro and Protobuf Enforcement
The Pulsar Schema Registry isn't just a place to store schemas; it's an active enforcer of data contracts between your producers and consumers, preventi.
Pulsar Seek: Jump to Message ID or Timestamp
Pulsar Seek lets you jump to a specific message by its ID or timestamp, but the real magic is how it fundamentally alters your read latency assumptions.
Pulsar Sequence Numbers: Duplicate Detection Setup
Pulsar's sequence number deduplication is actually a feature that guarantees exactly-once processing by allowing duplicates to be sent, but then silentl.
Pulsar Tiered Storage: Offload Old Data to S3
Pulsar's tiered storage is designed to be a transparent extension of your broker's local storage, allowing you to offload older data to cheaper, long-te.
Pulsar Topic Auto-Creation: Configure Default Policy
Pulsar Topic Auto-Creation: Configure Default Policy — practical guide covering pulsar setup, configuration, and troubleshooting with real-world examples.
Pulsar Topic Partitioning: Scale with Partitioned Topics
Pulsar's topic partitioning is how you break a single logical topic into multiple physical partitions, letting you scale throughput and parallelism way .
Pulsar Transactions: Exactly-Once Cross-Topic Processing
Pulsar transactions don't actually guarantee exactly-once processing in the way most people assume; they guarantee that a transactional producer will ei.
Pulsar Cluster Upgrade: Rolling Restart Without Downtime
A Pulsar cluster upgrade can be performed with zero downtime by carefully orchestrating a rolling restart of its components.
Pulsar ZooKeeper Bottleneck: Scale Metadata Operations
Pulsar's ZooKeeper ensemble is choking on metadata operations, preventing the system from scaling. Here's why and how to fix it
Fix Pulsar Send Timed Out Producer Errors
The Pulsar producer is failing to send messages to the broker because the network connection between them is dropping before the broker can acknowledge .
Fix Pulsar Service Unit Not Ready Errors
The Pulsar service unit is reporting NotReady because the underlying Zookeeper ensemble is unhealthy and unable to serve the quorum required by Pulsar b.
Fix Pulsar Subscription Not Found Errors
The Pulsar broker failed to locate a subscription on a topic because the subscription's metadata was lost or never properly registered.
Fix Pulsar Too Many Requests Rate Limit Errors
The Pulsar broker is rejecting client requests because it's exceeding its configured rate limits, preventing clients from publishing or consuming messag.
Fix Pulsar Topic Busy Errors
Pulsar topics are "busy" because the broker can't keep up with the rate of incoming writes or outgoing reads, leading to dropped requests and client err.
Fix Pulsar Topic Fenced Errors
Your Pulsar topic is fenced because a broker has taken over leadership for a partition that another broker is still actively serving.
Fix Pulsar Topic Terminated Errors
Your Pulsar topic is terminating because the broker is unable to manage the topic's state, specifically its metadata and ongoing operations, due to a pe.
Fix Pulsar Transaction Conflict Errors
A Pulsar transaction conflict error means a producer tried to commit a transaction that had already been committed or aborted by another producer.
Fix Pulsar Transaction Coordinator Not Found
The Pulsar Transaction Coordinator TC is failing to start because the ZooKeeper ensemble it relies on for metadata storage is unavailable or misconfigur.
Fix Pulsar Transaction Not Found Errors
The Pulsar transaction coordinator is failing to find transaction metadata it expects to have, leading to transaction timeouts and errors.
Fix Pulsar ZooKeeper Operation Failed Errors
The Pulsar broker is failing to perform operations against ZooKeeper because the broker's ZooKeeper client library is not correctly initialized or confi.
Fix Pulsar Acknowledge Timed Out Errors
The Pulsar broker is timing out while waiting for acknowledgment from a Pulsar client, meaning the client isn't confirming message consumption fast enou.
Fix Pulsar Authentication Failed Errors
The Pulsar authentication system is failing because client connections are being rejected by the broker, indicating a mismatch between the credentials p.
Fix Pulsar Authorization Failed Errors
Authorization is failing because the Pulsar broker is unable to verify the identity or permissions of the client attempting to access a topic.
Fix Pulsar Broker Metadata Error
The Pulsar broker is failing to write metadata to ZooKeeper because ZooKeeper itself is no longer accepting new connections from the broker, indicating .
Fix Pulsar Broker Service URL Not Configured
The Pulsar broker failed to register with ZooKeeper because its configured brokerServiceUrl was not discoverable by other components.
Fix Pulsar Bundle Conflict Errors
The Pulsar broker failed to assign a topic to a bundle because the bundle's metadata was out of sync with the topic's current assignment, indicating a m.
Fix Pulsar Message Checksum Mismatch Errors
The Pulsar broker Received a message with incorrect checksum error means a broker received a message where the data didn't match the checksum Pulsar cal.
Fix Pulsar Client Is Not Connected Errors
The Pulsar client is failing to connect to the broker because the underlying network or authentication mechanism is preventing the connection from being.
Fix Pulsar Connection Already Closed Error
The Pulsar client library is reporting a "Connection Already Closed" error because it's attempting to use a connection that the broker has already termi.
Fix Pulsar Consumer Already Closed Error
The Pulsar client library is failing to send messages to a broker because the producer object, which represents your application's connection to Pulsar,.
Fix Pulsar Consumer Assignment Errors
The Pulsar broker failed to assign partitions to your consumer because the consumer's subscription state was unexpectedly removed from the broker's inte.
Fix Pulsar Consumer Busy Exclusive Subscription
Your Pulsar consumer is getting stuck in a "busy" state because the broker is unable to acknowledge messages to it fast enough, leading to a backlog and.
Fix Pulsar Dispatcher Blocked Errors
The Pulsar dispatcher is blocking because a broker is unable to send data to a broker, leading to a backlog of messages and eventual timeouts.
Fix Pulsar Entry Log Not Found Errors
The Pulsar broker is failing to find the required segment entries in its bookkeeper bookies, meaning it can't serve read requests because the data it ne.
Fix Pulsar Incompatible Schema Errors
The Pulsar client, attempting to produce or consume messages, failed because the schema of the data it was trying to send or receive didn't match the sc.
Fix Pulsar Managed Ledger Errors
The Pulsar managed ledger component is failing to acknowledge writes, causing data loss and client timeouts because it's not properly flushing its inter.
Fix Pulsar Message Deduplication Failed
The Pulsar broker failed to acknowledge messages, indicating a failure in its internal state management or network communication, preventing reliable me.
Fix Pulsar Namespace Not Found Errors
Fix Pulsar Namespace Not Found Errors — practical guide covering pulsar setup, configuration, and troubleshooting with real-world examples.
Fix Pulsar Persistent Topic Not Found Errors
The Pulsar broker is failing to find metadata for a persistent topic, meaning it can't locate or access the topic's ledger in the BookKeeper cluster.
Fix Pulsar Producer Already Closed Error
A Pulsar producer is failing with an "Already Closed" error because the underlying connection to the broker has been shut down unexpectedly, and the pro.
Fix Pulsar Producer Queue Full Backpressure
The Pulsar producer's internal queue is full, causing it to stop sending messages to the broker because the broker is not acknowledging them fast enough.
Pulsar Acknowledgment: Cumulative vs Individual Ack
Pulsar's acknowledgment mechanism, often assumed to be a simple "message received" flag, is actually a sophisticated dance between producer, broker, and.
Pulsar Backpressure: Handle Slow Consumer Lag
A Pulsar consumer can fall behind its topic's producer, leading to a backlog of unacknowledged messages, which Pulsar calls "consumer lag" or "backpress.
Pulsar Batch Producer: Compress and Batch Messages
Pulsar's batch producer doesn't actually send messages one by one in the background; it groups them into larger chunks for efficiency.
Fix Pulsar Bookie Running Out of Disk Space
The Pulsar BookKeeper nodes bookies are failing because their local storage partitions are full, preventing them from writing new journal or ledger data.
Pulsar Bookie Storage: Manage Ledgers and Disk
Pulsar Bookie Storage: Manage Ledgers and Disk — practical guide covering pulsar setup, configuration, and troubleshooting with real-world examples.
Pulsar Broker Load Balancing: Rebalance Topic Ownership
Pulsar brokers don't actively balance topic ownership; they react to load by redistributing partitions based on configurable thresholds.
Fix Pulsar Broker Out of Memory: JVM Tuning
The Pulsar broker's JVM ran out of memory because the Java heap, intended to hold active data and metadata, was exhausted by excessive garbage collectio.
Pulsar Bundle Rebalance: Redistribute Topic Bundles
Pulsar doesn't actually "rebalance" topic bundles; it distributes them based on a weighted algorithm that aims for even resource utilization across brok.
Pulsar Managed Ledger Cache: Tune Eviction Policy
The Pulsar Managed Ledger Cache MLC evicts entries based on a Least Recently Used LRU policy by default, but this can lead to suboptimal performance if .
Pulsar Client Tuning: Consumer and Producer Config
Pulsar clients often feel like black boxes, but their performance is entirely tunable by understanding a few core concepts.
Pulsar Log Compaction: Retain Latest Value per Key
Pulsar's log compaction doesn't actually retain the latest value per key, it retains the first value after a compaction event for any given key.
Pulsar Subscription Types: Exclusive, Shared, Failover
Pulsar subscriptions are more than just queues; they're sophisticated mechanisms for consumers to reliably ingest messages from topics, and the type you.
Pulsar Dead Letter Topic: Handle Failed Messages
Pulsar's dead letter topic DLQ isn't just a place to dump bad messages; it's an active queue for retrying failed processing.
Pulsar Delayed Messages: Schedule Future Delivery
Pulsar's delayed message scheduling doesn't actually hold messages in memory; it cleverly uses a separate, dedicated topic to manage the delivery timest.
Pulsar Docker Standalone: Run Locally in Minutes
Pulsar Docker Standalone: Run Locally in Minutes — practical guide covering pulsar setup, configuration, and troubleshooting with real-world examples.
Pulsar EntryLog Format: Bookie Storage Internals
The EntryLog format in Apache Pulsar's BookKeeper storage is surprisingly inefficient at utilizing disk space for small messages, despite its sophistica.
Pulsar Subscription Patterns: Exclusive to Key-Shared
Pulsar subscriptions don't just deliver messages; they govern how those messages are consumed, and the distinction between "Exclusive" and "Key-Shared" .
Pulsar Functions: Stateless Event Processing
The most surprising thing about Pulsar Functions is that they are designed to be stateless, yet they can process events that are inherently stateful.
Pulsar Geo-Replication: Sync Topics Across Clusters
Pulsar's geo-replication is designed to keep identical copies of topics synchronized across different data centers, ensuring high availability and disas.
Pulsar HTTP Lookup: Service URL Resolution
The Pulsar HTTP lookup service isn't just a way to find brokers; it's the foundational mechanism for discovering the actual endpoints of your distribute.
Pulsar IO Connectors: Source and Sink Configuration
Pulsar IO connectors don't just move data; they orchestrate the entire lifecycle of data flowing into and out of Pulsar, acting as the unacknowledged gu.
Pulsar Bookie Journal Disk: Tune for Low Latency
The Pulsar Bookie journal disk is a critical component for ensuring low-latency writes and data durability, but it's often a bottleneck if not configure.
Pulsar JWT Token Rotation: Renew Auth Tokens
Pulsar JWT Token Rotation: Renew Auth Tokens — practical guide covering pulsar setup, configuration, and troubleshooting with real-world examples.
Pulsar JWT and TLS: Authentication Configuration
Pulsar's JWT and TLS authentication are often seen as two separate, independent security mechanisms, but they're actually deeply intertwined, with TLS a.
Pulsar on Kubernetes: Deploy with Helm Charts
Helm charts are the standard way to deploy Pulsar on Kubernetes, but they're more than just a deployment tool; they're your blueprint for a resilient, s.
Pulsar Large Messages: Chunking for 10MB+ Payloads
Pulsar doesn't actually support messages larger than 10MB by default, which is a bit of a surprise given how often you hit that limit.