IDR upgrade: Migrating IDR v2 replication setsSummaryOverview of migration from the legacy IDR replication, that is being phased out, to the next versions (V2) of IDR replication.ReleaseThe Utah release and aboveInstructionsLeveraging IDR v2 replication sets Background In Utah, ServiceNow introduced the next generation of messaging and replication service to the ServiceNow platform. Migrating to this next version will allow you to leverage many enhancements and get ahead of the migration process. Like the current IDR messaging, this next generation service is based on Kafka and leverages the Hermes messaging service. Hermes is a Now Platform messaging capability for internal and external data powers IDR and a number of new services. The Utah and Vancouver releases of IDR supports both legacy and V2 (Hermes) replication with legacy replication ending with the X release. All replication sets created prior to the Utah release are considered legacy replication sets. Legacy producer replication sets are compatible only with legacy consumer replication sets. Similarly, V2 producer replication sets are compatible only with V2 consumer replication sets. V2 replication sets in IDR use the Hermes Messaging Service for Kafka message transport and delivery, which replicates data faster, at scale, and with high reliability. Recommendations for Utah New Replications: All new replication sets should be created using V2 replication. To do so, make sure the Legacy check box is cleared to create a V2 replication set. Upgrading replications: In Utah, only certain replication sets are available to be automatically upgraded. To determine upgrade eligibility, look at the Upgrade Eligibility Column in the Producer replication set table. In Utah, legacy replication sets are eligible for upgrade to V2 when the following conditions are met: The producer replication set's outbound entry contains only one tableThe producer replication set has at least one, and only one, active consumer subscriptionThe Enable custom coalesce option is inactive in the producer replication setBoth the Discrete and Bi-Directional replication options are inactive in the producer replication setThe Enable transform option is inactive in both the producer and consumer replication sets Upgrading replication sets from legacy to V2 is a seamless process. Active data replication from the producer to consumer continues throughout the upgrade, this means you do not need to pause replication before you begin. Replication continues using the V2 replication sets after the upgrade is finished. An overview of the process shown below with the full upgrade process detailed in the documentation, please refer to this documentation for explicit instructions. The process to follow is: Upgrade the legacy producer replication setUpgrade the legacy consumer replication setSelect Begin upgrade on the consumer replication formActivate the new V2 replication set, subscribe to the new V2 consumer and resend the metadataTest replication by using the Start Dry Run buttonActivate by selecting Finish UpgradeDeactivate legacy producer replication set Recommendations for Vancouver New Replications: all new replication sets should be created using V2 replication. To do so make sure the Legacy check box is cleared to create a V2 replication set. Upgrading replications in Vancouver There are three scenarios: Producer and consumer are on Vancouver, then all replications sets are eligible for upgradeProducer is on Vancouver and eligible Consumer on Utah: then replication set is eligible for upgradeProducer is on Vancouver and ineligible Consumer on Utah: replication set cannot be upgraded As described above, Utah legacy sets have limitations on upgrade and so limit upgradability of Utah sets. An overview of the process shown below with the full upgrade process detailed in the documentation, please refer to this documentation for explicit instructions. The process to follow is: Upgrade the legacy producer replication setUpgrade the legacy consumer replication setSelect Begin upgrade on the consumer replication formActivate the new V2 replication set, subscribe to the new V2 consumer and resend the metadataTest replication by using the Start Dry Run buttonActivate by selecting Finish UpgradeDeactivate legacy producer replication set Compatibility If you upgrade a producer replication set to V2, you must upgrade the subscribed consumer replication sets to V2 as well. V2 producer replication sets are compatible only with V2 consumer replication sets, and legacy producer replication sets are only compatible with legacy consumer replication sets.