Re: EPICS, PostgreSQL, Archive Engine: doubts about how to use them

["Kasemir, Kay via Tech-talk" <tech-talk at aps.anl.gov>]

To store the history of samples, you have at least three options:

a) Run the phoebus data browser to sample live data from channel access or PV access, and then "export" the data from the plot. That only captures what was sampled while the data browser was running. You could similarly run "camonitor some_pv_name | tee archive.dat" to capture data into a file.

b) Or you run some service that takes samples in the background by using the archive engine for writing to Oracle/MySQL/Postgres/Timescaledb. That binary is the "archive-engine.zip" on https://controlssoftware.sns.ornl.gov/css_phoebus/nightly/ (which now combines what used to be a separate archive config tool and archive engine).

c) Or you use that archive appliance, https://slacmshankar.github.io/epicsarchiver_docs/, a similar service which uses its own binary data file format instead of a relational database.

To then look at the data, you can again use the phoebus data browser (after you configure phoebus to look at either Oracle/MySQL/Postgres/Timescaledb or the archive appliance), or you go directly to Oracle/MySQL/Postgres/Timescaledb or the archive applicance web service.

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From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of Abdalla Ahmad via Tech-talk <tech-talk at aps.anl.gov>
Sent: Thursday, January 12, 2023 3:46 AM
To: Oscar Ibañez <oscar.ibanez.spain.1980 at gmail.com>
Cc: tech-talk at aps.anl.gov <tech-talk at aps.anl.gov>
Subject: [EXTERNAL] RE: EPICS, PostgreSQL, Archive Engine: doubts about how to use them

 

Hello Oscar

Many years ago, we happened to use the RDB archive engine so I will give you what I remember from that time. The RDB archive engine is a server application installed on a separate server. Once configured, the engine will start save samples from the configured PVs. The role of CSS/Phoebus is that it contains the data browser tool. The data browser tool connects to the archive engine via the preferences and configurations you mentioned, then you can view archived data on the data browser tool. The archive engine is a java application consisting of two tools, the config tool and the engine. The config tool is used to load PV configuration into the RDB and the engine tool is used to start the archiver itself. Unfortunately I could not find download links for it.

Hope this helps.

Abdalla.

-----Original Message-----
From: Tech-talk <tech-talk-bounces at aps.anl.gov> On Behalf Of Oscar Ibañez via Tech-talk
Sent: Thursday, January 12, 2023 11:03 AM
To: tech-talk at aps.anl.gov
Subject: EPICS, PostgreSQL, Archive Engine: doubts about how to use them

Hi,

I am trying to set up a PostgreSQL RDMS to work together with EPICS to save some PV values. However, I am having doubts about how to do it, since the process is not clear to me.

First of all, I installed EPICS and I downloaded Phoebus. Both are running with no problem. In addition, I installed PostgreSQL. It seems to work fine. Then, I tried to learn how to connect EPICS and PostgreSQL, and I ended up reading Phoebus documentation about the RDB Archive Engine, and that was the point when I did no understand what I was doing.
https://gcc02.safelinks.protection.outlook.com/?url="">

The document says that I need to download the archive engine from:
https://gcc02.safelinks.protection.outlook.com/?url="">

But I can't find any archive engine in that place.

In addition, I am confused about the rol of Phoebus in this problem. Why do I need to set up any preference in the Phoebus configuration to use the Archive Engine? Phoebus is just a software to create and to display graphical screen to monitor/check the control system. If I run the Archive Engine, that software will save PV values in the PostgreSQL tables that I want. So, I don't understand the relationship between Phoebus and the Archive Engine, since the documentation is in the CSS web.

Any help would be useful.

Regards.

Óscar