Flow Server
The Flow Server answers questions about flow logs - the step-by-step record of how each call or request moved through SBN Media - so calls can be traced, searched, and analysed.
Overview
A *flow log* is a structured record of a single request's journey through the system: which service handled each step, when, how long it took, and whether it failed, all tied together by a trace identifier. The Flow Server answers queries against these records - tracing one call, searching across many, and producing summaries such as the slowest calls, the busiest devices, and error counts.
The flow logs are kept in a local SQLite database; the Flow Server reads from it.
- Runs: When configured. One per host.
- Required: Only where flow tracing and analytics are used. Not needed for basic call or alarm handling.
- Depends on: NATS and the SQLite database where the flow logs live.
Configuration
The Flow Server reads its store through the flow settings:
| Setting | Default | Description |
|---|---|---|
flow.engine | sqlite | Where flow logs are stored: sqlite, or file to read the plain-text log files only. |
flow.sqlite.path | flow.sqlite.db in the log folder | Where the SQLite flow database is kept. |
flow.retentionDays | 30 | How long flow logs are kept before they are removed automatically. |
flow.batch.maxRows / flow.batch.maxLatencyMs | 1000 / 500 | How records are grouped as they are written to the store. |
After changing settings in sbn-media.local.yaml, apply them with ./sbn-media config reload.
FAQ
What is a flow log?
A trace-linked record of one request's path through the system - in effect the timeline of a call, used for troubleshooting and analytics.
What does the Flow Server do?
It answers queries against those records - trace a single call, search across many, or produce summaries.
How long are flow logs kept?
For flow.retentionDays (30 days by default).
Do I need it?
Only where flow tracing or analytics are used.
Related pages
- SBN Media Overview (
SBN-Media/overview) - Installing and Configuring SBN Media (
SBN-Media/installation) - Watchdog (
SBN-Media/Platform/watchdog)