--- sourceDocument: Brazil ServiceNow AI Platform Capabilities sourceDocumentLink: https://www.servicenow.com/docs/r/servicenow-platform Release : - brazil ft:locale : - en-US ft:publication_title : - Brazil ServiceNow AI Platform Capabilities ft:clusterId : - platcap bundleId : - platcap workflow : - Platform --- # Explore # Exploring Hermes Messaging Service {#ariaid-title1} Release version: Brazil Updated September 10, 2026 ![](https://www.servicenow.com/docs/portal-asset/ico-clock) 4 minutes to read Summarize ![AI sparkle icon](https://servicenow.com/docs/portal-asset/ai-sparkle-icon) Summarized using AI This content was generated using new OpenAI-powered functionality. Results are provided on an as is basis and are not guaranteed to be accurate or complete. ## Summary of Exploring Hermes Messaging Service The Hermes Messaging Service integrates your ServiceNow® instance with your Apache Kafka environment, enabling seamless, asynchronous data exchange across your business systems. Built on Kafka, Hermes is a multi-tenant, multi-cluster data transport and queuing service designed to handle high-volume Kafka events with low latency. It simplifies and standardizes the flow of data, efficiently managing spikes in message traffic while providing diagnostic tools to monitor message health and performance. Show full answer Show less ## Key Features * **Event Management:** Hermes organizes data as events, which are records of system activities transmitted in near real-time. * **Topic and Partition Structure:** Events are grouped into topics and further divided into partitions to enable scalability and parallel processing, ensuring ordered delivery of messages with the same key. * **Namespaces:** Logical groupings of topics that help segment Kafka clusters or domains, particularly useful in domain-separated instances for access control. * **Kafka Cluster Hosting:** Hermes Kafka clusters are hosted within ServiceNow data centers to manage message delivery between producers (event senders) and consumers (event readers). * **User Roles:** Hermes administrators manage namespaces, topics, and monitor message payloads via the Hermes Messaging Service topic inspector, using both the ServiceNow instance and CLI tools. ## Benefits and Use Cases * **Integration Across ServiceNow Platform:** Multiple ServiceNow applications and integration points can publish and consume Kafka events via Hermes. * **Supported Applications:** * **Workflow Studio:** Enables exporting data from ServiceNow to external systems. * **Log Export Service (LES):** Securely exports log data to external data lakes for compliance and auditing. * **Stream Connect:** Facilitates triggering flows based on incoming Kafka events and sending outgoing Kafka messages. * **Instance Data Replication (IDR):** Enhances replication performance by utilizing Hermes for data transport. ## Limitations * Maximum message size is capped at 2 MB per message and per second for both production and consumption. * No limit on the number of topics, but each topic can have up to 32 partitions. * The total maximum partitions across all topics is 960. * Message retention is limited to 36 hours. * Supported compression formats for producing messages include GZIP, LZ4, and NONE. ## Next Steps ServiceNow customers can explore detailed guidance on configuring Hermes Messaging Service, managing namespaces and topics, exchanging data, and administering the service to maximize data integration efficiency and reliability. Learn about the Hermes Messaging Service and how it helps you manage the flow of data between your Kafka environment and your instance. ## Hermes Messaging Service overview {#exploring-hermes-messaging-service__section_ew2_kyl_5wb} Apache Kafka is an open-source data streaming platform that provides a single integration point for exchanging data across business systems in your organization. The Hermes Messaging Service enables you to integrate your Apache Kafka environment with your ServiceNow® instance to exchange data with these business systems. The Hermes Messaging Service is a multi-tenant, multi-cluster, data transport, and queuing service built on Apache Kafka that enables your instance to produce and consume large volumes of Kafka events. * Simplify and standardize asynchronous data transport between your Kafka environment and your ServiceNow instance. * Publish and process Kafka events at scale. Publish events to your Kafka environment from your ServiceNow instance and consume Kafka events from your external systems at a high volume with low latency. * Effectively process spikes and bursts in message volume to minimize performance impacts on your instance. * Manage the health and performance of message delivery using Hermes diagnostic tools. {#exploring-hermes-messaging-service__ul_xsy_3xg_sbc} ## Components {#exploring-hermes-messaging-service__section_gxt_m4v_bgc} Hermes uses the following components. Event : A record of something that happened, such as the creation of a log entry. Kafka uses events to transmit data between systems in near real time. An event includes a key and a value. Topic : A logical group of events. In Kafka, these events are transmitted as messages. Topics are used to group related events together. Events in a topic are organized using partitions. Partition : A topic is divided into partitions to support scalability and parallel processing. Each event is assigned to a partition based on its key. Events with the same key are always written to the same partition in order of arrival. Namespace : A logical grouping of topics. You can organize topics by namespace to indicate which Kafka cluster they come from. In a domain-separated instance, you can create a namespace for each domain to control access to specific topics. Hermes Kafka cluster : A Kafka cluster hosted in a ServiceNow data center. Hermes uses Kafka clusters to manage the delivery of messages between producers and consumers. Producer : A system or component that creates and sends events to a topic in the Hermes Kafka cluster. The producer sets the event key, which determines the partition where the event is stored. Consumer : A system or component that reads events from one or more topic partitions. Consumers process events in the order they appear within each partition. Consumers can read from multiple partitions simultaneously. ## Hermes Messaging Service users {#exploring-hermes-messaging-service__cf-exploring-parent-users} {#exploring-hermes-messaging-service__table_jws_fwg_sbc__entry__2} | User | Description | |-|-| | Hermes administrator | The Hermes admin defines namespaces for each Kafka cluster or domain and creates topic records in the instance or through the command-line interface (CLI). The Hermes admin monitors topics and views the payload of a message in a Hermes topic using the Hermes Messaging Service topic inspector. | [Table 1. Users] {#exploring-hermes-messaging-service__table_jws_fwg_sbc} ## Hermes Messaging Service workflow {#exploring-hermes-messaging-service__cf-exploring-parent-workflow} 1. In a domain-separated instance, the Hermes admin creates namespace records for different domains. 2. The Hermes admin creates topic records in the instance or through the CLI. 3. The Hermes admin updates or rescans topic records as needed in the instance. 4. The Hermes admin monitors topics and views message payloads using the Hermes Messaging Service topic inspector. {#exploring-hermes-messaging-service__cf-exploring-parent-workflow-ol} ## Benefits {#exploring-hermes-messaging-service__section_jyf_kjm_5wb} Different integration points and applications in the ServiceNow platform can use the Hermes Messaging Service to publish and ingest events. The Hermes Messaging Service is a ServiceNow AI Platform capability that is available as part of Stream Connect, Log Export Service (LES), and Instance Data Replication (IDR). {#exploring-hermes-messaging-service__table_pdp_ljm_5wb__entry__3} | Benefit | Application | Users | |-|-|-| | Export data from your ServiceNow instance to an external application using the Hermes Messaging Service with Workflow Studio. | [Flow Designer](https://www.servicenow.com/docs/access?context=flow-designer&version=brazil&pubname=brazil-application-development&ft:locale=en-US) | Administrator | | Export log data securely from your instance to your external data lake for reporting, auditing, or regulatory purposes by using the Hermes Messaging Service with the Log Export Service. | [Exploring Log Export Service (LES)](https://www.servicenow.com/docs/access?context=les-landing-page&version=brazil&pubname=brazil-platform-security&ft:locale=en-US) | Administrator | | Trigger flows from incoming Kafka events and trigger outgoing messages to your Kafka environment using the Hermes Messaging Service with Stream Connect. | [Using Stream Connect for Apache Kafka](https://www.servicenow.com/docs/access?context=stream-connect-apache-kafka&version=brazil&pubname=brazil-integrate-applications&ft:locale=en-US) | Administrator | | Improve the performance and processing efficiency of Instance Data Replication (IDR) by upgrading replication sets that you created prior to the Utah release to use the Hermes Messaging Service. | [Instance Data Replication](https://www.servicenow.com/docs/f7Em2C3B0IGNGY1iugpyYA "ServiceNow Instance Data Replication (IDR) copies data updates from one instance, called the producer instance, to one or more other instances called the consumer instances. IDR enables you to maintain consistent data across different instances. For example, you can synchronize data between different organizations in your company or even between different companies with separate instances.") | Administrator | [ ] {#exploring-hermes-messaging-service__table_pdp_ljm_5wb} ## Limitations {#exploring-hermes-messaging-service__section_asj_pbs_w5b} * Maximum message size: 2 MB * Maximum message size per second: 2 MB (produced or consumed) * Number of topics: No limit * Maximum number of partitions per topic: 32 partitions * Maximum number of partitions: 960 (across all external topics and internal topics used by Stream Connect, Log Export Service, and other ServiceNow® apps) * Retention policy: 36 hours * Supported compression types for producing messages to Hermes: GZIP, LZ4, and NONE. {#exploring-hermes-messaging-service__ul_v1m_knk_pvb} ## What to explore next {#exploring-hermes-messaging-service__cf-exploring-parent-links} To learn more about configuring and using the Hermes Messaging Service, see: * [Configuring Hermes Messaging Service](https://www.servicenow.com/docs/bVU1dV4vv4in9h1VPGuq2g "Learn how the Hermes Messaging Service is activated. Set up a secure connection to the Hermes Messaging Service.") * [Exchanging data using Hermes](https://www.servicenow.com/docs/R2PqKAjfFtnucCYt75ernQ "Produce and consume Kafka messages in your ServiceNow instance using the Hermes Messaging Service.") * [Managing namespaces and topics in Hermes](https://www.servicenow.com/docs/dmg6ZRTqqpbaTIl~wqrPRw "Organize and manage namespaces and topics in the Hermes Kafka cluster using the Hermes Messaging Service.") * [Administering Hermes Messaging Service](https://www.servicenow.com/docs/GROwAXsGiIWQwgLEsCODLA "Monitor the Hermes Messaging Service by viewing diagnostics and inspecting topics.") * [Hermes Messaging Service reference](https://www.servicenow.com/docs/8TaDsrQTLjH02n1JX2brWA "Reference topics provide details on the Hermes Messaging Service components and the security model.") {#exploring-hermes-messaging-service__ul_nws_fwg_sbc}