Temporal

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netflixOriginal article

How Temporal Powers Reliable Cloud Operations at Netflix | by Netflix Technology Blog | Dec, 2025 | Netflix TechBlog (opens in new tab)

Netflix has significantly enhanced the reliability of its global continuous delivery platform, Spinnaker, by adopting Temporal for durable execution of cloud operations. By migrating away from a fragile, polling-based orchestration model between its internal services, the engineering team successfully reduced transient deployment failures from 4% to a remarkable 0.0001%. This shift has allowed developers to write complex, long-running operational logic as standard code while the underlying platform handles state persistence and fault recovery. ### Limitations of Legacy Orchestration * **The Polling Bottleneck:** Originally, Netflix's orchestration engine (Orca) communicated with its cloud interface (Clouddriver) via a synchronous POST request followed by continuous polling of a GET endpoint to track task status. * **State Fragility:** Clouddriver utilized an internal orchestration engine that relied on in-memory state or volatile Redis storage, meaning if a Clouddriver instance crashed mid-operation, the deployment state was often lost, leading to "zombie" tasks or failed deployments. * **Manual Error Handling:** Developers had to manually implement complex retry logic, exponential backoffs, and state checkpointing for every cloud operation, which was both error-prone and difficult to maintain. ### Transitioning to Durable Execution with Temporal * **Abstraction of Failures:** Temporal provides a "Durable Execution" platform where the state of a workflow—including local variables and thread stacks—is automatically persisted. This allows code to run "as if failures don’t exist," as the system can resume exactly where it left off after a process crash or network interruption. * **Workflows and Activities:** Netflix re-architected cloud operations into Temporal Workflows (orchestration logic) and Activities (idempotent units of work like calling an AWS API). This separation ensures that the orchestration logic remains deterministic while external side effects are handled reliably. * **Eliminating Polling:** By using Temporal’s signaling and long-running execution capabilities, Netflix moved away from the heavy overhead of thousands of services polling for status updates, replacing them with a push-based, event-driven model. ### Impact on Cloud Operations * **Dramatic Reliability Gains:** The most significant outcome was the near-elimination of transient failures, moving from a 4% failure rate to 0.0001%, ensuring that critical updates to the Open Connect CDN and Live streaming infrastructure are executed with high confidence. * **Developer Productivity:** Using Temporal’s SDKs, Netflix engineers can now write standard Java or Go code to define complex deployment strategies (like canary releases or blue-green deployments) without building custom state machines or management layers. * **Operational Visibility:** Temporal provides a native UI and history audit log for every workflow, giving operators deep visibility into exactly which step of a deployment failed and why, along with the ability to retry specific failed steps manually if necessary. For organizations managing complex, distributed cloud infrastructure, adopting a durable execution framework like Temporal is highly recommended. It moves the burden of state management and fault tolerance from the application layer to the platform, allowing engineers to focus on business logic rather than the mechanics of distributed systems failure.

datadog3 min readCurated summary

Replication redefined: How we built a low-latency, multi-tenant data replication platform

Datadog built a managed, multi-tenant data replication platform to move data reliably across thousands of services without brittle, point-to-point integrations. The effort began by separating analytical search workloads from a shared PostgreSQL database, then evolved into automated pipeline provisioning with Temporal. The platform favors asynchronous replication to improve scalability and resilience, accepting limited replication lag in exchange for lower application latency and reduced operational coupling. ## Scaling Search Beyond PostgreSQL - A shared PostgreSQL database initially provided low-latency access, ACID guarantees, and low operational cost. - As data volumes grew, complex joins and aggregations became increasingly slow. - Datadog’s Metrics Summary page had to join: - 82,000 active metrics - 817,000 metric configurations - Page latency reached approximately 7 seconds at p90, while repeated facet changes generated additional expensive queries. - Index and disk bloat, memory pressure, VACUUM and ANALYZE overhead, and rising I/O wait further reduced throughput. - Rather than continuing to optimize PostgreSQL for analytical search, Datadog moved search and aggregation workloads to a dedicated search platform. - Data was denormalized during replication, producing document-oriented indexes better suited to faceted search. - The resulting system reduced page-load times by as much as 97%—from roughly 30 seconds to 1 second—while maintaining about 500 ms of replication lag. ## Automating Pipeline Provisioning with Temporal Provisioning a replication pipeline required coordinating multiple systems and configuration steps: - Enabling PostgreSQL logical replication with `wal_level`. - Creating users and assigning replication permissions. - Configuring publishers and replication slots. - Deploying Debezium instances to capture PostgreSQL changes. - Creating Kafka topics and mapping them to Debezium instances. - Adding heartbeat tables to monitor replication and prevent excessive WAL retention. - Configuring sink connectors to write Kafka data into the search platform. Manual management became increasingly difficult across many pipelines and data centers. Datadog used Temporal workflows to split provisioning into modular, repeatable tasks and combine them into higher-level orchestrations. This reduced errors, improved consistency, and allowed engineers to create and modify pipelines without repeating complex operational procedures. ## Choosing Asynchronous Replication - Synchronous replication provides strong consistency by waiting for replicas to acknowledge each write. - However, it increases latency and operational complexity, particularly across distributed environments. - Asynchronous replication allows the primary system to acknowledge writes immediately while replicas catch up afterward. - Datadog selected the asynchronous model because it decouples application performance from network latency and replica availability. - The trade-off is temporary replication lag during failures or periods of pressure, but the model offers better scalability and resilience for high-throughput systems. Datadog’s experience suggests that replication should be treated as a managed platform rather than a collection of custom integrations. Separating workloads, automating provisioning, and choosing asynchronous delivery can improve performance and reliability while reducing the operational burden on individual engineering teams.

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