Apache Pinot vs Esper

Apache Pinot is a free, open-source distributed OLAP datastore for real-time analytics and user-facing workloads. It ingests streaming data from Apache Kafka, Apache Pulsar, and AWS Kinesis, plus batch data from Hadoop, Spark, Amazon S3, Azure ADLS, and Google Cloud Storage. Streaming and batch sources can be combined into one queryable table. Pinot provides SQL through a query editor and REST API, with JDBC, Java, Python, and Golang clients for applications. Project materials advertise P90 query latency in the tens of milliseconds on petabyte-scale data and capacity for hundreds of thousands of concurrent queries per second. Logical namespaces provide multitenancy. Security features include HTTP Basic Authentication, ACLs, TLS, mutual TLS, and row-level security filters in version 1.4.0 and later. Superset, Tableau, and Power BI can connect as BI tools. Official installation guidance covers Docker and Kubernetes with Helm. The self-hosted plan is listed at free.

Esper is a language, compiler, and runtime for complex event processing and streaming analytics in Java and .NET. Its Event Processing Language extends SQL with expressions over events and time. The compiler turns EPL into bytecode that can be packaged in JAR files. Esper and NEsper embed inside Java or .NET processes rather than running as standalone servers. The in-memory runtime is described as memory-efficient and low-latency and does not require external storage or services. Adapters handle CSV, JMS, HTTP, Kafka, database, and socket input and output, with JMX metrics exposure. Queries can join event streams with web services and relational databases through SQL-query or method-invocation joins. Esper Enterprise Edition adds scale-out architecture with elastic scaling, load balancing, fault tolerance, and multi-datacenter support using Apache Kafka and Apache Zookeeper. Listed uses include business-process monitoring, financial applications such as fraud detection, network and application monitoring, and sensor networks. Esper 9.0.0 is listed under GNU GPL (GPL v2); commercial redistribution licenses are available. Production support has Bronze, Silver, and Gold levels, plus a Developer Seat for how-to questions.