Why architecture matters here
Hive fails on metastore bottlenecks, bad partitioning, missed stats, and LLAP misconfig. Architecture matters because engine + metastore + storage decide throughput.
The architecture: every piece explained
The top strip is the request path. Client JDBC/CLI. HS2 lifecycle. Metastore schema + partitions. Execution engine Tez / MR / Spark.
The middle row is acceleration. LLAP daemons long-lived + cached. ACID tables delta + compactor. File formats ORC / Parquet. Ranger + Kerberos security.
The lower rows are ops. Partitioning + bucketing. Statistics + CBO. Ops — metastore backup + upgrade + concurrent writers.
End-to-end flow
End-to-end: SQL query lands on HS2. Metastore consulted for partitions. Tez plan produced with CBO using stats. LLAP daemons serve cached hot data. ORC files scanned; predicate pushdown active. Result returned. ACID transaction commits via delta files; compactor rewrites in background.