Apache Ignite vs Apache ZooKeeper

Apache Ignite is a free, open-source, memory-first distributed SQL database for high-velocity workloads. It keeps data primarily in memory, with persistence available through AIPERSIST, and supports ACID transactions across partitions using Raft consensus. MVCC snapshot isolation enables non-blocking reads. SQL access includes JDBC drivers, a Table API and native APIs, while catalog-driven schema management allows column and index changes without stopping the cluster. DataStreamer handles high-throughput writes with backpressure control. Native clients are listed for Java, .NET, C++ and Python, alongside AWS, Azure, GCE and Spring extensions. Built-in operational capabilities include authentication, SSL/TLS security, OpenTelemetry metrics, recovery snapshots and backups. Listed uses include event stream processing, microservices state management, session management and AI/ML feature stores. Ignite is self-hosted and available through binary, source, Docker and Maven/Gradle options. The project identifies Ignite 2 as a long-term-support release recommended for existing deployments.

Apache ZooKeeper has no write-up on Specifiction yet; its figures are above.