Disclaimer: This is work in progress intended to consolidate information from various sources for learning purposes. For the latest information please consult the documentation (see the links below)!
Last updated: 9-Mar-2025
         
       | 
    
| Real-Time Intelligence architecture [4] | 
[Microsoft Fabric] Eventhouses
- [def]
 - a service that empowers users to extract insights and visualize data in motion
 - offers an end-to-end solution for
 - event-driven scenarios
 - ⇐ rather than schedule-driven solutions [1]
 - a workspace of databases
 - can be shared across projects [1]
 - allows to manage multiple databases at once
 - sharing capacity and resources to optimize performance and cost
 - provides unified monitoring and management across all databases and per database [1]
 - provide a solution for handling and analyzing large volumes of data
 - particularly in scenarios requiring real-time analytics and exploration [1]
 - designed to handle real-time data streams efficiently [1]
 - lets organizations ingest, process, and analyze data in near real-time [1]
 - provide a scalable infrastructure that allows organizations to handle growing volumes of data, ensuring optimal performance and resource use.
 - preferred engine for semistructured and free text analysis
 - tailored to time-based, streaming events with structured, semistructured, and unstructured data [1]
 - allows to get data
 - from multiple sources,
 - in multiple pipelines
 - e.g. Eventstream, SDKs, Kafka, Logstash, data flows, etc.
 - multiple data formats [1]
 - data is automatically indexed and partitioned based on ingestion time
 - designed to optimize cost by suspending the service when not in use [1]
 - reactivating the service, can lead to a latency of a few seconds [1]
 - for highly time-sensitive systems that can't tolerate this latency, use Minimum consumption setting [1]
 - enables the service to be always available at a selected minimum level [1]
 - customers pay for
 - the minimum compute level selected [1]
 - the actual consumption when the compute level is above the minimum set [1]
 - the specified compute is available to all the databases within the eventhouse [1]
 - {scenario} solutions that includes event-based data
 - e.g. telemetry and log data, time series and IoT data, security and compliance logs, or financial records [1]
 - KQL databases
 - can be created within an eventhouse [1]
 - can either be a standard database, or a database shortcut [1]
 - an exploratory query environment is created for each KQL Database, which can be used for exploration and data management [1]
 - data availability in OneLake can be enabled on a database or table level [1]
 - Eventhouse page
 - serves as the central hub for all your interactions within the Eventhouse environment [1]
 - Eventhouse ribbon
 - provides quick access to essential actions within the Eventhouse
 - explorer pane
 - provides an intuitive interface for navigating between Eventhouse views and working with databases [1]
 - main view area
 - displays the system overview details for the eventhouse [1]
 - {feature} Eventhouse monitoring
 - offers comprehensive insights into the usage and performance of the eventhouse by collecting end-to-end metrics and logs for all aspects of an Eventhouse [2]
 - part of workspace monitoring that allows you to monitor Fabric items in your workspace [2]
 - provides a set of tables that can be queried to get insights into the usage and performance of the eventhouse [2]
 - can be used to optimize the eventhouse and improve the user experience [2]
 - {feature} query logs table
 - contains the list of queries run on an Eventhouse KQL database
 - for each query, a log event record is stored in the EventhouseQueryLogs table [3]
 - can be used to
 - analyze query performance and trends [3]
 - troubleshoot slow queries [3]
 - identify heavy queries consuming large amount of system resources [3]
 - identify the users/applications running the highest number of queries[3]
 - {feature} OneLake availability
 - {benefit} allows to create one logical copy of a KQL database data in an eventhouse by turning on the feature [4]
 - users can query the data in the KQL database in Delta Lake format via other Fabric engines [4]
 - e.g. Direct Lake mode in Power BI, Warehouse, Lakehouse, Notebooks, etc.
 - {prerequisite} a workspace with a Microsoft Fabric-enabled capacity [4]
 - {prerequisite} a KQL database with editing permissions and data [4]
 - {constraint} rename tables
 - {constraint} alter table schemas
 - {constraint} apply RLS to tables
 - {constraint} data can't be deleted, truncated, or purged
 - when turned on, a mirroring policy is enabled
 - can be used to monitor data latency or alter it to partition delta tables [4]
 - {feature} robust adaptive mechanism
 - intelligently batches incoming data streams into one or more Parquet files, structured for analysis [4]
 - ⇐ important when dealing with trickling data [4]
 - ⇐ writing many small Parquet files into the lake can be inefficient resulting in higher costs and poor performance [4]
 - delays write operations if there isn't enough data to create optimal Parquet files [4]
 - ensures Parquet files are optimal in size and adhere to Delta Lake best practices [4]
 - ensures that the Parquet files are primed for analysis and balances the need for prompt data availability with cost and performance considerations [4]
 - {default} the write operation can take up to 3 hours or until files of sufficient size are created [4]
 - typically the files have 200-256 MB
 - the value can be adjusted between 5 minutes and 3 hours [4]
 - {warning} adjusting the delay to a shorter period might result in a suboptimal delta table with a large number of small files [4]
 - can lead to inefficient query performance [4]
 - {restriction} the resultant table in OneLake is read-only and can't be optimized after creation [4]
 - delta tables can be partitioned to improve query speed [4]
 - each partition is represented as a separate column using the PartitionName listed in the Partitions list [4]
 - ⇒ OneLake copy has more columns than the source table [4]
 
[1] Microsoft Learn (2025) Microsoft Fabric: Eventhouse overview [link]
[2] Microsoft Learn (2025) Microsoft Fabric: Eventhouse monitoring [link]
KQL - Kusto Query Language
SDK - Software Development Kit
RLS - Row Level Security
RTI - Real-Time Intelligence



