Outages and Recovery Objectives (RTO / RPO)

When a cloud outage disrupts a Namespace, Temporal Cloud takes measures to maintain the Namespace's availability and data durability. The time it takes to recover from the outage is called the "recovery time." The amount of data (event histories) lost is called the "recovery point." A durable system should have a low recovery time and recovery point.

To help users plan for keeping critical Workflows available during a cloud outage, Temporal Cloud publishes goals for the recovery time and recovery point for each kind of outage. These goals are called the Recovery Time Objective (RTO) and Recovery Point Objective (RPO). These objectives are complementary to Temporal Cloud's Service Level Agreement (SLA).

Types of outages Temporal Cloud designs around

Temporal Cloud is engineered to withstand four broad categories of cloud outage. The categories are listed below in order of how commonly they occur in the real world. For each category, Temporal has experienced the outage in production, and the corresponding Temporal Cloud features have successfully mitigated the impact for real customer Namespaces.

Availability Zone outage

An Availability Zone (AZ) is akin to an isolated datacenter managed by a cloud hyperscaler, with independent power, networking, and cooling infrastructure. Each cloud region contains multiple AZs, and an individual AZ can fail due to events such as hardware failure, power loss, or a localized network partition.

Historically, AZ outages are the most common type of outage in the cloud, and Temporal Cloud has weathered many of them transparently to its customers.

Blast Radius: A single Availability Zone within a single cloud region. Because every Namespace's components are spread across at least three AZs, the blast radius to Temporal Cloud users is typically zero — Namespaces stay operational with little to no downtime. However, the outage will take out any Workers the user is running in that AZ. We recommend spreading Workers across multiple AZs to mitigate this.

Temporal Cloud feature to mitigate this outage: Every Namespace is automatically spread across at least three Availability Zones, and any Namespace can handle a single AZ failure without disruption to end-user Temporal operations. High Availability features are not required to keep Temporal Cloud operations running through an AZ outage.

SLA inclusion: Included in the SLA calculation. Any errors during an AZ outage count toward SLA credits, since AZ resilience is within Temporal's responsibility.

If two AZs fail simultaneously, Temporal Cloud treats the event as a Cloud Region outage. In that case, Namespaces in the region may be impacted, including those using Same-region Replication (in Preview).

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When an AZ fails, Temporal may also trigger a failover on Namespaces that have High Availability enabled, as a precaution in case the outage scope expands. You can opt out of this behavior by disabling Temporal-managed failovers on the Namespace.

RTO and RPO

When using Temporal Cloud (no additional features required):

• Near-zero RTO. When a single AZ fails, the remaining two AZs continue serving requests without a failover, so end users see little to no disruption.
• Zero RPO. Writes to Workflow state are synchronously replicated across all three AZs before being acknowledged back to the Client, so an AZ failure cannot cause data loss.

Cell outage

Temporal Cloud runs on a cell architecture. Each cell contains the software and services necessary to host a Namespace, and components within a cell are distributed across at least three Availability Zones. Cells provide a strong unit of isolation: a problem inside one cell does not propagate to other cells.

Example causes: failure of a sub-component within the cell (for example, an individual database becoming unavailable) or a software bug introduced in a new deploy to the cell.

Blast Radius: One cell--and the Namespaces within that cell--within a single region. Even though your Workers will remain healthy, they will not be able to process Workflows because the Namespace is down.

Temporal Cloud feature to mitigate this outage: Multi-region Replication (GA) and Multi-cloud Replication (GA) replicate a Namespace into another cell in a different region or different cloud provider. Same-region Replication (Preview) replicates a Namespace into another cell in the same region. With any of these features enabled, an outage that disrupts a single cell can be mitigated by failing the Namespace over to its replica.

SLA inclusion: Included in the SLA calculation. Any errors during a cell outage count toward SLA credits, since mitigating cell outages is within Temporal's responsibility.

Cell-level disruptions occur from time to time, and Temporal's replication and failover tooling has restored affected Namespaces in real-world incidents.

RTO and RPO

When using Same-region Replication, Multi-region Replication, or Multi-cloud Replication for Temporal-managed failover:

• RTO under 20 minutes. Temporal detects the disruption and fails the Namespace over to its replica cell.
• RPO under 1 minute. Asynchronous replication keeps the replica close to the active cell.

Even though the RPO target is under 1 minute, data is virtually never "lost" thanks to Temporal's built-in Recovery and Conflict Resolution process, which reconciles state between the active and replica when a failover occurs.

Cloud Region outage

A cloud region as a whole can become degraded, with effects that span beyond any single cell or Availability Zone.

Example causes: failure of a key cloud service in the region (for example, the cloud provider's DNS resolver) causing cascading failures, two or more Availability Zones failing simultaneously, or network partitions between the region and other regions.

Blast Radius: All Namespaces and Workers within a single cloud region are potentially affected. Namespaces and Workers in other regions of the same cloud — and in other clouds — are unaffected.

Temporal Cloud feature to mitigate this outage: Multi-region Replication and Multi-cloud Replication place the replica outside the affected region, so a Namespace can fail over and continue serving Workflows. Same-region Replication does not protect against a Cloud Region outage, since the replica resides in the same region.

SLA inclusion: Included in the SLA calculation only for Namespaces that have Multi-region Replication or Multi-cloud Replication enabled with Temporal-managed failovers — in those cases, Temporal can mitigate the outage. For Namespaces without these features, a Cloud Region outage is excluded from the SLA calculation, as it is beyond Temporal's control to mitigate.

If two or more regions in the same cloud provider experience an outage simultaneously, Temporal Cloud treats the event as a Cloud-wide outage.

Regional outages are less common than cell or AZ outages, but they happen. During the AWS us-east-1 incident on October 20, 2025, Temporal Cloud's regional failover kept customer Namespaces running.

RTO and RPO

When using Multi-region Replication or Multi-cloud Replication for Temporal-managed failover:

• RTO under 20 minutes. Temporal detects the regional disruption and fails the Namespace over to its replica in another region.
• RPO under 1 minute. Asynchronous replication keeps the replica close to the active region.

Even though the RPO target is under 1 minute, data is virtually never "lost" thanks to Temporal's built-in Recovery and Conflict Resolution process, which reconciles state between the active and replica when a failover occurs.

Cloud-wide outage

On rare occasions, an issue affects two or more regions of a single cloud provider at once. Any simultaneous outage of two or more regions in the same cloud provider is treated as a cloud-wide outage.

Example causes: a software bug rolled out to every region of a cloud provider that triggers cascading failures across the provider's infrastructure, or two or more regions in the same cloud experiencing independent regional outages at the same time.

Blast Radius: Most or all regions of a single cloud provider. Every Namespace and every Worker hosted in that cloud is potentially affected.

Temporal Cloud feature to mitigate this outage: Multi-cloud Replication places the replica in a different cloud provider entirely, so the Namespace can fail over even when an entire cloud provider goes down.

SLA inclusion: Included in the SLA calculation only for Namespaces that have Multi-cloud Replication enabled with Temporal-managed failovers — in those cases, Temporal can mitigate the outage. For Namespaces without this feature, a cloud-wide outage is excluded from the SLA calculation, as it is beyond Temporal's control to mitigate.

Cloud-wide outages are the rarest category, but they have occurred. Multi-cloud Replication is designed to keep Namespaces running through such events.

RTO and RPO

When using Multi-cloud Replication for Temporal-managed failover:

• RTO under 20 minutes. Temporal detects the cloud-wide disruption and fails the Namespace over to its replica in a different cloud provider.
• RPO under 1 minute. Asynchronous replication keeps the replica close to the active region, even across cloud providers.

Even though the RPO target is under 1 minute, data is virtually never "lost" thanks to Temporal's built-in Recovery and Conflict Resolution process, which reconciles state between the active and replica when a failover occurs.

How High Availability replication works

To achieve the lowest RPO and RTO, Temporal Cloud offers High Availability features that keep Workflows operational with minimal downtime. When High Availability is enabled on a Namespace, the user chooses a region to place a "replica" that will take over in the event of a failure. The location of the replica determines the type of replication used and the categories of outage it can handle:

• Multi-region Replication places the active and replica in different regions on the same cloud (for example, AWS us-east-1 and AWS us-west-2).
• Multi-cloud Replication places the active and replica in different cloud providers (for example, AWS and GCP).
• Same-region Replication (Preview) places the active and replica in the same region.

Temporal always places the active and replica in different cells.

As Workflows progress in the active region, history events are asynchronously replicated to the replica. Because replication is asynchronous, High Availability does not impact the latency or throughput of Workflow Executions in the active region. If an outage hits the active region or cell, Temporal Cloud will fail over to the replica so that existing Workflow Executions will continue to run and new Workflow Executions can be started.

Explaining Temporal Cloud's RTO and RPO

The Recovery Point Objective and Recovery Time Objective for Temporal Cloud depend on the type of outage and which High Availability feature your Namespace has enabled. Temporal Cloud can only set an RPO and RTO for cases where it has the ability to mitigate the outage. Therefore, the published RPOs and RTOs apply to Namespaces that have the corresponding type of replication and have enabled Temporal-initiated failovers, which comes enabled by default.

Summary table

Outage type	Applicable Namespaces	RPO	RTO
Availability Zone outage	All Namespaces	Zero	Near-zero
Cell outage	Namespaces with Same-region, Multi-region, or Multi-cloud Replication	Under 1 minute	Under 20 minutes
Cloud Region outage	Namespaces with Multi-region or Multi-cloud Replication	Under 1 minute	Under 20 minutes
Cloud-wide outage	Namespaces with Multi-cloud Replication	Under 1 minute	Under 20 minutes

Notes:

• The above goals are only applicable to Namespaces that have enabled Temporal-initiated failovers, which comes enabled by default. Temporal-initiated failovers are initiated by Temporal's tooling and/or on-call engineers without user action. Users can always initiate a failover on their Namespace, even when Temporal-initiated failovers are enabled. In an outage, a user-initiated failover will not cancel out or accidentally reverse a Temporal-initiated failover.

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Temporal highly recommends keeping Temporal-initiated failovers enabled. When Temporal-initiated failovers are disabled, Temporal Cloud cannot set an RPO and RTO for that Namespace, because it cannot control when or if the user will trigger a failover.

• The above goals are for unplanned cloud outages. They do not apply to user-initiated failovers during healthy periods (e.g., for DR drills). Read about triggering a failover to see how a Namespace failover should perform during healthy periods.

• As soon as a cloud outage resolves, Temporal's on-call engineers will work to restore service to Namespaces that were not protected by High Availability. A cloud outage can leave lingering effects in Temporal's systems and applications, even after the cloud provider restores the underlying service. Because of this, affected Namespaces may not be immediately available when the underlying service is restored. An affected Namespace's outage may last longer than the cloud provider's outage.

• All Namespaces are backed up every 4 hours. If an outage causes data loss on a Namespace that was not protected by High Availability, then Temporal will use the backup to restore as much data as feasible.

• Temporal has internal goals and measurements for Recovery Time and Recovery Point, but does not publish the achieved Recovery Time and Recovery Point for each incident.

Explaining the RPO

Temporal's Recovery Point is different from a traditional Recovery Point

In a traditional database, data within the Recovery Point window may be permanently lost during a failover. In Temporal Cloud, that data is not lost. Cloud data stores are engineered for extreme durability (commonly 99.999999999%, or "11 nines"), so any data acknowledged by Temporal Cloud is durably persisted. After the outage resolves, Temporal's Recovery and Conflict Resolution process automatically syncs that data back into the Namespace.

The Recovery Point Objective therefore reflects the maximum data that may be temporarily unavailable in the replica at the moment of failover, not the maximum data that could be permanently lost.

Temporal has put extensive work into tools and processes that minimize the recovery point and achieve its RPO for Temporal-initiated failovers, including:

• Best-in-class data replication technology that keeps the replica up to date with the active.

• Monitoring, alerting, and internal SLOs on the replication lag for every Temporal Cloud Namespace.

However, user actions on a Namespace can affect the recovery point. For example, suddenly spiking into much higher throughput than a Namespace has seen before could create a period of replication lag where the replica falls behind the active.

Temporal provides a replication lag metric for each Namespace. This metric approximates the recovery point the Namespace would achieve in a worst case failure at that given moment.

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Temporal recommends monitoring the replication lag and alerting should it rise too high, e.g., above 1 minute.

Explaining the RTO

The Recovery Time for a given incident is measured from the moment the incident begins to cause abnormal Namespace operation — for example, when unavailability or error rates rise above an acceptable level — to the moment the Namespace is restored to full functionality.

For most incidents, the vast majority of the Recovery Time is spent detecting the incident, determining the affected boundary (a single cell, a region, or an entire cloud), and deciding to fail Namespaces over to their replicas. The actual time to complete the failover is usually a very small piece of the Recovery Time.

This Recovery Time covers only the Temporal Namespace. Your application's overall Recovery Time also depends on having enough healthy Workers that can reach the Namespace and process Workflows. Maintaining sufficient Worker capacity that can reach the replica region (or replica cloud) during a failover is your responsibility.

How Temporal achieves a low Recovery Time

Temporal has put extensive work into tools and processes that minimize the recovery time and achieve its RTO for Temporal-initiated failovers, including:

• History events are replicated asynchronously. This ensures that the Namespace can still run workflows in the active region even if there are networking blips or outages with the replica region.

• Outages are detected automatically. We have extensive internal alerting to detect disruptions to Namespaces, and are ever improving this system.

• Battle-tested Temporal Workflows that execute failovers of all Temporal Cloud Namespaces in a given region quickly.

• Regular drills where we fail over our internal Namespaces to test our tooling.

• Expert engineers on-call 24/7 monitoring Temporal Cloud Namespaces and ready to assist should an outage occur.

How users can achieve a lower Recovery Time

To achieve the lowest possible recovery times, Temporal recommends that you:

• Keep Temporal-initiated failovers enabled on your Namespace (the default)
• Invest in a process to detect outages and trigger a manual failover.

Users can trigger manual failovers on their Namespaces even if Temporal-initiated failovers are enabled. There are several benefits to combining a manual failover process with Temporal-initiated failovers:

• You can detect outages that Temporal doesn't. In the cloud, regional outages don't affect all services equally. It's possible that Temporal--and the services it depends on--are unaffected by the outage, even while your Workers or other cloud infrastructure are disrupted. If you monitor services in your critical path and alert on unusual error rates, you may catch outages before Temporal Cloud does.

• You can sequence your failovers in a particular order. Your cloud infrastructure probably contains more pieces than just your Temporal Namespace: Temporal Workers, compute pools, data stores, and other cloud services. If you manually fail over, you can choose the order in which these pieces switch to the replica region. You can then test that ordering with failover drills and ensure it executes smoothly without data consistency issues or bottlenecks.

• You can proactively fail over more aggressively than Temporal. While the 20-minute RTO should be sufficient for most use cases, some may strive to hit an even lower RTO. For workloads like high frequency trading, auctions, or popular sporting events, an outage at the wrong time could cause tremendous lost revenue per minute. You can adopt a posture that fails over more eagerly than Temporal does. For example, you could trigger a manual failover at the first sign of a possible disruption, before knowing whether there's a true regional outage.

• Even if you have robust tooling to detect an outage and trigger a failover, leaving Temporal-initiated failovers enabled provides a "safety net" in case your automation misses an outage. It also gives Temporal leeway to preemptively fail over your Namespace if we detect that it may be disrupted soon, e.g., by a rolling failure that has impacted other Namespaces but not yours, yet.

Comparing RTO and SLA

Temporal has both a Recovery Time Objective (RTO) and a Service Level Agreement (SLA). They serve complementary purposes and apply in different situations.

Aspect	RTO	SLA
What is it?	An objective, or high-priority goal, for the total time that an outage disrupts a Namespace.	A contractual agreement that sets an upper bound on the service error rate, with financial repercussions.
How is it measured?	The achieved recovery time is measured in terms of minutes per outage.	The achieved service error rate is measured in terms of error rate per month.
How is the calculation performed?	The achieved recovery time in a given outage is the total time between when a disruption to a Namespace began and when the Namespace was restored to full functionality, either after a failover to a healthy region or after the outage has been mitigated.	Temporal measures the percentage of requests to Temporal Cloud that fail, and applies a formula to get the final percentage for the month.
Do partial degradations count?	Most outages contain periods of partial degradation where some percentage of Namespace operations fail while the rest complete as normal. When they disrupt a Namespace, periods of partial degradation count in the calculation of the recovery time.	Partial degradations only partially count for the service error rate calculation. A 5-minute window with a 10% error rate would count less than a 5-minute window with a 100% error rate.
What is excluded?	For partial degradations, what counts as a disruption to a Namespace is subject to Temporal's expert judgment, but a good rule of thumb is a service error rate >=10%.	We exclude outages that are out of Temporal's control to mitigate, e.g., a failure of the underlying cloud provider infrastructure that affects a Namespace without High Availability and Temporal-initiated failovers enabled. If a Namespace has the relevant High Availability feature and has Temporal-initiated failovers enabled, then Temporal can act to mitigate the outage and it does usually count against the SLA. Full exclusions on the SLA page.

The following examples illustrate the RTO and SLA calculations for different types of in a regional outage. These hypothetical Namespaces are based on actual Temporal Cloud performance in a real-world outage.

Suppose that region middle-earth-1 experienced a cascading failure starting at 10:00:00 UTC, causing various instances and machines to fail over time. Temporal's automatic failover triggered for all Namespaces and completed at 10:15:00 UTC.

• Namespace 0 was in the region but its cell was not affected by the outage. The only downtime it had was for a few seconds during the failover operation. It experienced a near-zero Recovery Time, and its service error rate was negligible. Graceful failover was successful, and this Namespace achieved a recovery point of 0.

• Namespace 1_A was in the region and its cell experienced a partial degradation that caused 10% of requests to fail in the first 5 minutes, 25% in the second five minutes, and 50% in the third five minutes. Since it was significantly impacted from 10:00:00 to 10:15:00, its Recovery Time was 15 minutes. If it had no other service errors that month, then its service error rate for the month would be: ( (1 - 10%) + (1 - 25%) + (1 - 50%) + 8925 * 100% ) / 8928 = 99.990%. (Note: there are 8928 5-minute periods in a 31-day month.) Graceful failover was successful, and this Namespace achieved a recovery point of 0.

• Namespace 1_B was in the same cell as Namespace 2_A, so it also experienced a partial degradation that caused 10% of requests to fail. However, its owner detected the outage via their own tooling and decided to manually fail over at 10:05:00. This Namespace achieved a recovery time of 5 minutes and a service error rate of ( 1 * (1 - 10%) + 8927 * 100% ) / 8928 = 99.998%. Graceful failover was successful, and this Namespace achieved a recovery point of 0.

• Namespace 2_A was in the region and its cell was fully network partitioned at the start of the outage, causing 100% of requests to fail. Since it was significantly impacted from 10:00:00 to 10:15:00, its Recovery Time was 15 minutes. If it had no other service errors that month, then its service error rate for the month would be: ( 3 * (1 - 100%) + 8928 * 100% ) / 8640 5-minute periods per month = 99.97%. Because the Namespace was network partitioned, graceful failover did not succeed, and forced failover was used. The recovery point achieved was equal to the replication lag at the time of the network partition, which was a few seconds.

• Namespace 2_B was in the region and was fully network partitioned, causing 100% of requests to fail. However, its owner detected the outage via their own tooling and decided to manually fail over at 10:05:00. This Namespace achieved a recovery time of 5 minutes and a service error rate of ( 1 5-minute periods * (1 - 100%) + 8639 5-minute periods * 100% ) / 8640 5-minute periods per month = 99.99%. Because the Namespace was network partitioned, graceful failover did not succeed, and forced failover was used. The recovery point achieved was equal to the replication lag at the time of the network partition, which was a few seconds.

All of the above Namespaces were in the affected region and beat the 1-minute RPO. But they achieved varying recovery times and service error rates.

• Notice how Namespace 1_A and Namespace 2_A were both automatically failed over with the same recovery time but different service error rates. Notice how Namespace 2_B and Namespace 1_A happen to have the same service error rate but different recovery times. This illustrates how RTO and SLA can differ, even in the same outage. Both are valuable tools for Temporal Cloud users to measure the availability of their Namespaces.

• Notice how the Namespaces that were manually failed over (Namespace 1_B and Namespace 2_B) achieved lower recovery times than the Namespaces that were automatically failed over (Namespace 1_A and Namespace 2_A). This illustrates how proactive, aggressive manual failover can achieve a better recovery time than automatic failover.