NAME

       bulk_loader - PgQ consumer that loads urlencoded records to slow databases

SYNOPSIS

       bulk_loader.py [switches] config.ini

DESCRIPTION

       bulk_loader is PgQ consumer that reads url encoded records from source queue and writes
       them into tables according to configuration file. It is targeted to slow databases that
       cannot handle applying each row as separate statement. Originally written for
       BizgresMPP/greenplumDB which have very high per-statement overhead, but can also be used
       to load regular PostgreSQL database that cannot manage regular replication.

       Behaviour properties: - reads urlencoded "logutriga" records. - does not do partitioning,
       but allows optionally redirect table events. - does not keep event order. - always loads
       data with COPY, either directly to main table (INSERTs) or to temp tables (UPDATE/COPY)
       then applies from there.

       Events are usually procuded by pgq.logutriga(). Logutriga adds all the data of the record
       into the event (also in case of updates and deletes).

QUICK-START

       Basic bulk_loader setup and usage can be summarized by the following steps:

        1. pgq and logutriga must be installed in source databases. See pgqadm man page for
           details. target database must also have pgq_ext schema.

        2. edit a bulk_loader configuration file, say bulk_loader_sample.ini

        3. create source queue

               $ pgqadm.py ticker.ini create <queue>

        4. Tune source queue to have big batches:

               $ pgqadm.py ticker.ini config <queue> ticker_max_count="10000" ticker_max_lag="10 minutes" ticker_idle_period="10 minutes"

        5. create target database and tables in it.

        6. launch bulk_loader in daemon mode

               $ bulk_loader.py -d bulk_loader_sample.ini

        7. start producing events (create logutriga trggers on tables) CREATE OR REPLACE TRIGGER
           trig_bulk_replica AFTER INSERT OR UPDATE ON some_table FOR EACH ROW EXECUTE PROCEDURE
           pgq.logutriga(<queue>)

CONFIG

   Common configuration parameters
       job_name
           Name for particulat job the script does. Script will log under this name to
           logdb/logserver. The name is also used as default for PgQ consumer name. It should be
           unique.

       pidfile
           Location for pid file. If not given, script is disallowed to daemonize.

       logfile
           Location for log file.

       loop_delay
           If continuisly running process, how long to sleep after each work loop, in seconds.
           Default: 1.

       connection_lifetime
           Close and reconnect older database connections.

       log_count
           Number of log files to keep. Default: 3

       log_size
           Max size for one log file. File is rotated if max size is reached. Default: 10485760
           (10M)

       use_skylog
           If set, search for [./skylog.ini, ~/.skylog.ini, /etc/skylog.ini]. If found then the
           file is used as config file for Pythons logging module. It allows setting up fully
           customizable logging setup.

   Common PgQ consumer parameters
       pgq_queue_name
           Queue name to attach to. No default.

       pgq_consumer_id
           Consumers ID to use when registering. Default: %(job_name)s

   Config options specific to bulk_loader
       src_db
           Connect string for source database where the queue resides.

       dst_db
           Connect string for target database where the tables should be created.

       remap_tables
           Optional parameter for table redirection. Contains comma-separated list of
           <oldname>:<newname> pairs. Eg: oldtable1:newtable1, oldtable2:newtable2.

       load_method
           Optional parameter for load method selection. Available options:

       0
           UPDATE as UPDATE from temp table. This is default.

       1
           UPDATE as DELETE+COPY from temp table.

       2
           merge INSERTs with UPDATEs, then do DELETE+COPY from temp table.

LOGUTRIGA EVENT FORMAT

       PgQ trigger function pgq.logutriga() sends table change event into queue in following
       format:

       ev_type

           (op || ":" || pkey_fields). Where op is either "I", "U" or "D", corresponging to
           insert, update or delete. And pkey_fields is comma-separated list of primary key
           fields for table. Operation type is always present but pkey_fields list can be empty,
           if table has no primary keys. Example: I:col1,col2

       ev_data
           Urlencoded record of data. It uses db-specific urlecoding where existence of = is
           meaningful - missing = means NULL, present = means literal value. Example:
           id=3&name=str&nullvalue&emptyvalue=

       ev_extra1
           Fully qualified table name.

COMMAND LINE SWITCHES

       Following switches are common to all skytools.DBScript-based Python programs.

       -h, --help
           show help message and exit

       -q, --quiet
           make program silent

       -v, --verbose
           make program more verbose

       -d, --daemon
           make program go background

       Following switches are used to control already running process. The pidfile is read from
       config then signal is sent to process id specified there.

       -r, --reload
           reload config (send SIGHUP)

       -s, --stop
           stop program safely (send SIGINT)

       -k, --kill
           kill program immidiately (send SIGTERM)

                                            03/13/2012                             BULK_LOADER(1)