Upgrading legacy replication sets to V2 in Instance Data Replication

  • Release version: Zurich
  • Updated July 31, 2025
  • 2 minutes to read
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    Summary of Upgrading legacy replication sets to V2 in Instance Data Replication

    ServiceNow's Instance Data Replication (IDR) has transitioned from legacy replication sets to improved V2 replication sets starting with the Zurich release. Legacy replication sets, which utilized an older Kafka message transport system, are deprecated and must be upgraded to V2 to ensure continued data replication. V2 replication sets leverage the ServiceNow Hermes Messaging Service, providing faster, scalable, and more reliable data replication.

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    Key Features

    • Hermes Messaging Service Integration: V2 replication sets use this AI Platform capability for enhanced Kafka message transport and delivery.
    • Seamless Upgrade Process: Upgrading from legacy to V2 replication sets occurs without interrupting active data replication between producer and consumer instances.
    • Compatibility Requirements: Both producer and consumer instances must be on the Utah release or higher for upgrade eligibility.
    • Upgrade Eligibility Check: Eligibility is confirmed via the Upgrade Eligibility column in the Consumer Subscriptions related list of the producer replication set.
    • Data Retention: Data sent from a V2 producer is retained in the message queue for 24 hours.
    • Rollback Capability: If any issues occur during the upgrade, IDR automatically rolls back to the previous state.

    Key Outcomes

    • Improved Replication Performance: Faster and more reliable data replication across instances.
    • Continued Data Replication: Upgrading ensures ongoing replication support as legacy sets are deprecated.
    • Enhanced Scalability: V2 replication sets handle larger data volumes efficiently.
    • Backward Compatibility: Upgraded producer sets require corresponding consumer sets to be upgraded to maintain compatibility and performance benefits.

    Practical Considerations for ServiceNow Customers

    • Identify legacy replication sets created before the Utah release and confirm their eligibility for upgrade.
    • Ensure all involved instances (producer and consumer) are running Utah or later releases.
    • Upgrade replication sets either by creating new V2 sets or upgrading existing legacy ones following documented procedures.
    • Monitor the Upgrade Eligibility status in the Consumer Subscriptions related list prior to starting the process.
    • Expect uninterrupted data replication during the upgrade, minimizing operational impact.

    Improve message processing and replication performance by upgrading your legacy replication sets in IDR to V2.

    Legacy and V2 replication sets

    Important:
    Legacy replication sets are deprecated in the Zurich release. To continue replicating data, you must upgrade all legacy replication sets to V2.
    • Legacy replication sets use a ServiceNow Kafka message transport and delivery implementation that was created prior to the Utah release. All replication sets created prior to the Utah release are considered legacy replication sets.

      Beginning with the Washington DC release, you can no longer create legacy replication sets.

    • V2 replication sets use the ServiceNow Hermes Messaging Service for Kafka message transport and delivery, which replicates data faster, at scale, and with high reliability. The Hermes Messaging Service is a ServiceNow AI Platform capability that's automatically enabled when the IDR plugin (com.glide.idr) is activated. All replication sets created after the Washington DC release are V2 replication sets.
    Note:
    Data sent from a V2 producer replication set is retained in the message queue for 24 hours.

    Upgrading legacy replication sets

    Upgrade your eligible legacy replication sets to V2 to take advantage of the benefits provided by Hermes. Upgrading replication sets from legacy to V2 is a seamless process. Active data replication from the producer to consumer continues throughout the upgrade, which means you don't need to pause replication before you begin. Replication continues using the V2 replication sets after the upgrade is finished.

    You can either create new V2 replication sets or upgrade existing legacy replication sets to V2. See Upgrade legacy replication sets in Instance Data Replication.

    Upgrade eligibility

    Legacy replication sets are eligible for upgrade to V2 when both the producer and consumer instance are on Utah or higher. Note that some Utah legacy replication sets aren't eligible for upgrade to V2, depending on their configuration (for example, the replication set can't be bidirectional or discrete).

    You can confirm upgrade eligibility by viewing the producer replication set and checking the Upgrade Eligibility column in the Consumer Subscriptions related list.

    • If the value for each subscribed consumer is Eligible, you can begin the upgrade process by following the steps in Upgrade legacy replication sets in Instance Data Replication.
    • If the value for a subscribed consumer is Not eligible, this means that either the consumer instance isn't on Utah or higher, or the consumer replication set is on Utah, but isn't eligible for upgrade to V2 because of its configuration.

    For details on which types of legacy replication sets are eligible for upgrade in Utah, refer to the "Upgrading legacy replication sets to V2" topic in the Utah version of the IDR documentation.

    Compatibility

    V2 producer replication sets are compatible only with V2 consumer replication sets.

    If you upgrade a producer replication set to V2, you must upgrade the subscribed consumer replication sets to V2 as well to take advantage of the V2 processing improvements.