influxdata / influxdb-relay

Service to replicate InfluxDB data for high availability
MIT License
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Question regarding recovery procedure and shard ids #60

Open msoltyspl opened 7 years ago

msoltyspl commented 7 years ago

Hi,

I have 2 questions about the basic recovery example from the readme:

1) shard id Essentially do we have any guarantee that this will be the same for both influx databases, which - outside of having some databases and retention policies identical - know really nothing about each other ? ITOW if I backup shard X of database Y and retention policy Z from server DB1 - do I have any guarantee that X will be the same on DB2 ? From what I saw, the shard backups are just plain tar files with full paths to relevant tsm files (so if X can differ and influxd itself is not prepared for such restoration case ...)

2) live restoration Formally, influxdb documentation claims that: "Note: Restoring from backup is only supported while the InfluxDB daemon is stopped."

OTOH, the readme file says it's ok to do the resotration if the relevant shard/policy/db combination is no longer written to. Are there no other risks in this context (e.g. maybe something related to metadata or anything else) ?