OpenTSDB Schema

[Mostafa Gaber]

I have a question regarding the schema of OpenTSDB and how a datapoint is stored in HBase.

In the manual->schema page, an example was presented:
myservice.latency.avg 1292148123 42 reqtype=foo host=web42

The row key is the metric + base timestamp (round to 10 min) + tagname-tagvalue pair(s).
The column is 2 bytes, delta of timestamp and 4 flag bits.

Are all data points stored under the same column family and the possible columns under this column family are 2^16?

Why is the time stamp rounded to 10 min? Is that 10 min period fixed or configured to OpenTSDB?

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Best Regards,
Mostafa Ead

[tsuna]

On Mon, Jul 18, 2011 at 2:52 PM, Mostafa Gaber <moustaf...@gmail.com> wrote:
> Are all data points stored under the same column family and the possible

Yes, OpenTSDB uses only a single family.

> columns under this column family are 2^16?

2^14 - 1, because there are 16 bits but 4 of them are reserved. So
4095 columns per row max.

> Why is the time stamp rounded to 10 min? Is that 10 min period fixed or
> configured to OpenTSDB?

It's a compile-time constant, and it's no longer 10 minutes, it's 60
minutes. See http://groups.google.com/group/opentsdb/browse_thread/thread/14f33338a8c3d383
Did the docs mention 10 minutes somewhere that needs to be updated?

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Benoit "tsuna" Sigoure
Software Engineer @ www.StumbleUpon.com

[Mostafa Gaber]

Thanks for your reply.

Ya, I found it 10 minutes in this document: http://opentsdb.net/schema.html