NAME

deltadb_query - query historical data stored by the catalog server.

SYNOPSIS

deltadb_query --db [source_directory] --from [starttime] --to [endtime] [--filter [expr]] [--where [expr]] [--output [expr]]

DESCRIPTION

deltadb_query is a tool that examines and displays historical data of the catalog server. (If given the -H option, the catalog server will record historical data in a format known as DeltaDB, hence the name of this tool.) The results can be displayed as a stream of time-ordered updates or as summaries of properties across all records over time. This is useful for reporting, for example, the total resources and clients served by a large collection of servers over the course of a year.

A paper entitled DeltaDB describes the operation of the tools in detail (see reference below).

ARGUMENTS

--db path

Query this database directory.

--file path

Query the data stream in this file.

--from time

(required) The starting date and time of the query in an absolute time like "YYYY-MM-DD HH:MM:SS" or "YYYY-MM-DD" or a relative time like 5s, 5m, 5h, 5d to indicate five seconds, minutes, hours, or days ago, respectively.

--to time

The ending time of the query, in the same format as the --from option. If omitted, the current time is assumed.

--every interval

The intervals at which output should be produced, like 5s, 5m, 5h, 5d to indicate five seconds, minutes, hours, or days ago, respectively.

--epoch

Causes the output to be expressed in integer Unix epoch time, instead of a formatted time.

--filter expr

(multiple) If given, only records matching this expression will be processed. Use --filter to apply expressions that do not change over time, such as the name or type of a record.

--where expr

(multiple) If given, only records matching this expression will be displayed. Use --where to apply expressions that may change over time, such as load average or storage space consumed.

--output expr

(multiple) Display this expression on the output.

JX QUERY LANGUAGE

The --filter, --where, and --output options all make use of the JX query language, which is described URL(here,http://cctools.readthedocs.io/jx).

In addition, the --output clauses may contain one of the following reduction functions:

COUNT Give the count of items in the set.
SUM Give the sum of the values in the set.
FIRST Give the first value encountered in the set.
LAST Give the last value encountered in the set.
MIN Give the minimum value in the set.
MAX Give the maximum value in the set.
AVERAGE Give the average value of the set.
UNIQUE Give a list of unique values in the set.

(The UNIQUE function can be applied to any record type, while the other reduction functions assume numeric values.)

By default, reductions are computed at local scope. This means the reduction is computed across the set of records available at each periodic time step. If the prefix GLOBAL is added to a reduction, then the reduction is computed across every record over time.

For example, this:

--output 'UNIQUE(name)' --every 7d

will display all of the names in the database, at seven day intervals. However, it will not display records that are created and deleted between those seven day intervals. In comparison, this:

--output 'GLOBALUNIQUE(name)' --every 7d

will display all of the names encountered over the last seven days, at seven day intervals.

EXAMPLES

To show 1 week worth of history starting on 15 April 2013:

% deltadb_query --db /data/catalog.history --from 2013-04-15 --to 2015-04-22

To show all history after 1 March 2013:

% deltadb_query --db /data/catalog.history --from 2013-03-01

To show the names of fred's chirp servers where load5 exceeds 2.0:

% deltadb_query --db /data/catalog.history --from 2013-03-01 --filter 'owner=="fred" && type=="chirp"' --where 'load5>2.0' --output name --output load5

To show the average load of all servers owned by fred at one hour intervals:

% deltadb_query --db /data/catalog.history --from 2013-03-01 --filter 'owner=="fred" && type=="chirp"' --output 'AVERAGE(load5)' --every 1h

To show the project names of all Work Queue applications running at a given time:

% deltadb_query --db /data/catalog.history --at 2020-12-01 --filter 'type=="wq_master"' --output 'UNIQUE(project)'

To show the number of managers, tasks, and cores in use for all Work Queue applications:

% deltadb_query --db /data/catalog.history --from 2020-01-01 --to 2021-01-01 --filter 'type=="wq_master"' --output 'COUNT(name)' --output 'SUM(tasks_running)' -- output 'SUM(cores_inuse)'

The raw event output of a query can be saved to a file, and then queried using the --file option, which can accelerate operations on reduced data. For example:

% deltadb_query --db /data/catalog.history --from 2020-01-01 --to 2021-01-01 --filter 'type=="wq_master"' > wq.data
% deltadb_query --file wq.data --output 'COUNT(name)' --output 'SUM(tasks_running)' -- output 'SUM(cores_inuse)'