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)