.. _tutorials_archiving: ************************** Maintain waveform archives ************************** You will ... * Set up :ref:`slarchive` with its necessary bindings * Control the life-time of waveforms * Access waveforms Pre-requisites for this tutorial: * Have SeisComP installed * Tutorial on :ref:`adding a new station` * Tutorial on :ref:`real-time data acquisition` so that you have local data for GE stations. Alternatively you may already obtain real-time waveform data from somewhere else (see :ref:`tutorials_waveforms`). Afterwards/Results/Outcomes: * Save real-time data in a local archive for later processing. * See :term:`miniSEED` day files for GE stations in your local :ref:`waveform archive `. Time range estimate: * 20 minutes Related tutorial(s): * Tutorial on :ref:`tutorials_servefdsnws` * Tutorial on :ref:`tutorials_waveformplayback` ---------- Motivation ========== Without activating waveform archiving, your local :ref:`Seedlink server ` will only keep waveforms for a short period of time. This makes it hard to review old events, for example. :ref:`slarchive` is therefore set up and used for archiving real-time waveforms from a seedlink server. In this example, we'll arrange for keeping waveforms for one week. Before starting, you'll need ensure to have access to readl-time data from a :ref:`seedlink` server. To make seedlink bindings for your stations see the tutorials :ref:`tutorials_geofon_waveforms` or :ref:`tutorials_waveforms`. Background ========== :ref:`slarchive` collects data and archives it locally in the directory defined by :confval:`archive` using a :term:`SDS` file system structure of nested subdirectories and systematically named files. For working with the archived data, read the section on :ref:`tutorials_archiving-access`. Setup ===== :ref:`slarchive` requires a module configuration and bindings. You may configure slarchive using :ref:`scconfig` or by command-line actions. In scconfig ----------- #. Under the Modules tab, go to Acquisition, and select :program:`slarchive`. Here you can see the default parameters used. By default, :program:`slarchive` connects to your local Seedlink server, and archives to your local disk. #. Under the System tab, select the line for :program:`slarchive`, and click "Enable module(s)" button at the top. #. Under Bindings: On RHS right-click "slarchive" to add an slarchive profile. Name it 'week', to keep waveforms for 7 days, and click 'Ok'. The new profile appears in the (bottom right corner of :program:`scconfig`. Double click on the profile to open its settings. Unlock the box labeled "keep", and change the default from 30 to 7. Once you have a binding profile, drag it over all the stations it should apply to, under "Networks" on the left-hand side of the bindings tool. .. warning:: The name 'week' is just a label. Its functionality comes from changing the value of the `keep` parameter. Changing the *name* of a binding profile does not change its function. .. note:: You can also choose which channels should be archived, using the ":confval:`selectors`" box. For instance, you may collect data at several sample rates, and only wish to archive the highest rate. If you collect LH, BH, HH streams at 0.1, 20, and 100 samples per second, respectively, you might retain only the HH streams, by setting ":confval:`selectors`" to "HH". #. Then return to System, and click 'Update configuration'. Make sure the :program:`slarchive` module, or no module, is selected. #. Restart :program:`slarchive`. #. Adjust the :ref:`concepts_RecordStream` for making use of the archived waveforms from within a :term:`GUI` or automatic data processing modules. Command line ------------ You will need to edit each of your top-level key files to refer to a new binding profile. e.g. .. code-block:: sh $ cd ~/seiscomp/etc/key $ vi station_GR_CLL Add the line `slarchive:week` to whatever lines are already there. Afterwards it will look something like this .. code-block:: properties # Binding references global:BH scautopick:default seedlink:geofon slarchive:week Repeat this for the top-level key file of each station you wish this binding to apply to. Now create the binding profile in the key directory. This is a file with a name corresponding to the binding profile name; here: 'week' .. code-block:: sh $ cd ~/seiscomp/etc/key $ mkdir slarchive $ vi slarchive/profile_week # Number of days the data is kept in the archive. This requires purge_datafile # to be run as cronjob. keep = 7 $ seiscomp enable slarchive $ seiscomp update-config slarchive $ seiscomp restart slarchive slarchive is not running starting slarchive Data life cycle --------------- Left unattended, your disk will eventually fill up with archived data since :ref:`slarchive` itself does not delete any data. Deleting files ~~~~~~~~~~~~~~ To prevent your file system from filling up you may delete data using a script like `purge_database`, provided with |scname|. The script considers duration set by the *keep* parameter in slarchive bindings for defining the number of days to keep the data in your archive. The script can be run once per day using the `cron` feature of your system. The command .. code-block:: sh $ seiscomp print crontab will print a number of lines with suggested actions to the terminal. Type `crontab -e` and insert these lines into the crontab file for your user (typically `sysop`). Exit your crontab editor. Displaying your crontab should now show a line for `purge_database`. .. code-block:: sh $ crontab -l 20 3 * * * /home/sysop/seiscomp/var/lib/slarchive/purge_datafiles >/dev/null 2>&1 [There may be other lines too.] This shows you that the `purge_datafiles` script will run every day at 3:20 a.m. .. note:: If you examine the `purge_datafiles` script, you will see that all it does is looking for files with a last modified time older than a certain number of days ago. The number of days to keep can be set station-by-station using the ARCH_KEEP feature. A convenient way to do this for many stations is with multiple slarchive binding profiles, one for each length of time desired. Extending disk space ~~~~~~~~~~~~~~~~~~~~ In case your file system fills up with data and you do not wish to delete old ones, you may add an additional harddisk and configure :confval:`archive` of :program:`slarchive` to store the new data there. Thereafter you may configure the *combined* or the *sdsarchive* :ref:`global_recordstream` to read the data from both sources. Verification ------------ * If :ref:`seedlink` is configured correctly, a new station's streams appear in output from :ref:`slinktool` .. code-block:: sh $ slinktool -Q : | grep CLL GR CLL HHZ D 2020/04/01 01:11:57.6649 - 2020/04/01 07:28:49.0299 GR CLL HHE D 2020/04/01 01:11:57.6649 - 2020/04/01 07:28:45.0299 GR CLL HHN D 2020/04/01 01:11:57.6649 - 2020/04/01 07:28:39.2299 This shows three streams being acquired from station 'CLL'. The second time shown is the time of the most recent data for each stream. * If :ref:`slarchive` is configured correctly, waveform data for the station appears in :program:`slarchive`'s SDS archive directory: .. code-block:: sh $ ls -l seiscomp/var/lib/archive/2020/GR/CLL total 12 drwxr-xr-x 2 user user 4096 Apr 1 06:30 HHE.D drwxr-xr-x 2 user user 4096 Apr 1 06:30 HHN.D drwxr-xr-x 2 user user 4096 Apr 1 06:30 HHZ.D $ ls -l seiscomp/var/lib/archive/2020/GR/CLL/HHZ.D/ total 12728 -rw-r--r-- 1 user user 5492224 Mar 31 00:04 GR.CLL..BHZ.D.2020.090 -rw-r--r-- 1 user user 7531008 Apr 1 00:03 GR.CLL..BHZ.D.2020.091 You may read these data files directly using :ref:`scrttv`, e.g.: .. code-block:: sh $ scrttv seiscomp/var/lib/archive/2020/GR/CLL/HHZ.D/* .. _tutorials_archiving-access: Access to Archived Data ======================= Archived waveforms can be read or provided in multiple ways depending on the application. * Offline reading with :ref:`scrttv`: Read miniSEED files directly using :ref:`scrttv`, e.g.: .. code-block:: sh $ scrttv seiscomp/var/lib/archive/2020/GR/CLL/HHZ.D/* * Automatically for data processing: |scname| modules such as :ref:`scautopick` or :ref:`scolv` can read data from SDS archive with the *sdsarchive* :ref:`global_recordstream` when running on the same computer. * External clients: You may provide the data to clients on other computers using :ref:`scwfas` or :ref:`fdsnws` both providing data via :cite:t:`fdsn`. * Direct file access: For directly fetching :term:`miniSEED` waveform data from archive you may use :ref:`scart` or Linux commands. You may combine scart with other modules avoiding redundant file storage. Examples: .. code-block:: sh $ scart -dEsv -t 2025-02-01T01:00~2025-02-01T01:00 /archive | scrttv - $ scart -dEsv -t 2025-02-01T01:00~2025-02-01T01:00 /archive | scautopick -I - -d localhost --ep --playback