CQL, clusters, and calm.
Native CQL with keyspace and table browsing, paged queries with named parameters, compression, SSH tunneling, and full-primary-key row edits — plus a trace inspector that turns ALLOW FILTERING warnings into real schema proposals.
Cassandra · ScyllaDB · native CQL · SSH tunneling
The trace Mongrel shows for your query.
Click any stage below to see latency, replica detail, and what Mongrel would suggest. Same view you get inside the workbench.
// Replica read · SSTable scan
Scanned the full partition on each replica — ALLOW FILTERING bypasses every index path. 12 SSTables touched, 3,100 tombstones skipped, 4 Bloom filter false positives.
-- ks.events · cassandra-dc1-r3 (RF=3, CL=LOCAL_QUORUM) SELECT event_id, status, payload FROM ks.events WHERE user_id = 'u_4821' AND created_at > '2026-06-01' AND status = 'paid' ALLOW FILTERING; -- 1.2s · 18,402 rows scanned · 12 SSTables -- ✗ ALLOW FILTERING scans the full partition -- ✓ Proposal: materialized view keyed (user_id, status) CREATE MATERIALIZED VIEW ks.events_by_user_status AS SELECT * FROM ks.events WHERE user_id IS NOT NULL AND status IS NOT NULL AND created_at IS NOT NULL AND event_id IS NOT NULL PRIMARY KEY ((user_id, status), created_at, event_id);
What Mongrel ships for Cassandra.
Keyspace & table browser
Browse keyspaces, tables, views, and types with full schema detail — clustering order, TTL, compaction, and gc_grace.
Paged CQL with parameters
Run CQL with named parameters and driver-level paging. Large partitions stream in pages instead of freezing the grid.
Query trace inspector
Break down coordinator, partition lookup, replica read, and paging latency per stage — tombstones and SSTable hits included.
Full-primary-key row edits
Edit rows safely with the complete primary key enforced. No accidental cross-partition writes, ever.
SSH tunneling & TLS
Reach private clusters through SSH bastions, with TLS client certs and Cassandra/ScyllaDB native authentication.
Compression-aware transport
LZ4, Snappy, and Zstd compression on the wire. Negotiated per connection, visible in the connection profile.
ALLOW FILTERING advisor
Slow CQL gets flagged with the scan cost, then rewritten into a proper table or materialized view keyed for the query.
Cluster topology view
See datacenters, racks, token ranges, and node health across the ring — Cassandra 4.x/5.0 and ScyllaDB alike.
Import, export, copy
CSV and JSON in and out, schema-aware copy between Cassandra, ScyllaDB, and any other engine Mongrel supports.