> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vortexiq.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Pending Compactions, Apache Cassandra KPI card, Vortex IQ Nerve Centre

> Cassandra-distinctive - from nodetool compactionstats / PendingTasks MBean. Backlog = SSTables stacking up, read amplification rising.

**[Nerve Centre KPIs](/nerve-centre/kpi-cards/cassandra) · [Audit Profile](/nerve-centre/kpi-cards/cassandra/audit) · [Sentiment Settings](/nerve-centre/kpi-cards/cassandra/sentiment)**

## At a glance

* **Category:** Compaction & Storage
* **Type:** Key Metrics
* **Chart:** kpi
* **Format:** number
* **Time window:** RT
* **Alert trigger:** >100 sustained

## Calculation

Cassandra-distinctive - from nodetool compactionstats / PendingTasks MBean. Backlog = SSTables stacking up, read amplification rising.

## Known limitations

*Known limitations, FAQs, or reconciliation notes specific to this card. Replace this block when authored.*