Revision history for Perl extension Helios.
2.50_3160  Sat Aug 04 14:11:00 2012
	Significant changes to configuration subsystem.
	-Helios::Config->init() now clears all already parsed config 
	 data structures.  The init() method should normally only be 
	 called once.
	-Helios::Service: significant changes to how Helios::Service 
	 interacts with Helios::Config.  
	 -Added ConfigClass() method to specify alternate config modules 
	  (like JobClass() and Helios::Job).  
	 -Added initConfig() method to call init() for whatever config 
	  module is specified and $INIT_CONFIG_CLASS to keep track of what
	  config module has been initialized.  
	 -The prep() method will now only call initConfig() to initialize 
	  the config module once, but will always call parseConfig() to 
	  update current config parameters (unless a cached config was 
	  given when LAZY_CONFIG_UPDATE is active).
	 -getConfigFromIni() and getConfigFromDb() have been rewritten 
	  to use Helios::Config (or whatever ConfigClass() is set).
	  However, use of these methods is now deprecated, as 
	  Helios::Config and its subclasses can be used directly.
	-t/1.t and t/2.t have been updated to test Helios::Config 
2.50_3070  Sun Jul 29 16:37:00 2012 Added DOUBLE_CLUTCH_INTERVAL config param to support
	 WORKER_MAX_TTL functionaity.  Updated copyright info.
2.50_3060  Sat Jul 28 17:34:00 2012
	-Fixed Helios::Config->init() RT#78616
	-Added Helios::Error::ConfigError exception to throw in case of 
	 configuration problems.
2.50_3040  Thu Jul 26 23:59:00 2012
	-changes to Helios::ObjectDriver::DBI and to properly
	 handle database connections between parent and child processes
	 (prevents children from attempting to disconnect parent db
	 connections) changed new worker_blitz_factor param to 
	 WORKER_BLITZ_FACTOR for consistency with OVERDRIVE, HOLD, etc.
	 WORKER_BLITZ_FACTOR is now dynamically updated instead of set 
	 only at runtime.
	-Updated lib/Bundle/ so it's proper package name is 
	 Bundle::Helios, not Bundle::Helios::Generic (oops).
2.50_2910  Mon Jul 16 21:18:00 2012
	-Helios::Service: changes to dbConnect(), jobsWaiting() to prevent 
	 clobbering of Helios::ObjectDriver::DBI connections in some 
	-Helios::Service: replaced try {} otherwise block with 
	 eval {} or do in getFuncidFromDb().
	-Updated copyright notices in README and to include
	 notifications of Logical Helion and Six Apart code 
	 (the notices were intact on the code in question).
2.50_2860  Sun Jul 15 22:14:00 2012
	-NEW Helios::Config module to handle parsing of configuration 
	 information, and modifications to Helios::Service and 
	 to use it instead of the old getConfigFromIni() and 
	 getConfigFromDb() methods.
2.50_2850  Wed Jul 11 23:36:00 2012  
	-Helios::TheSchwartz and Helios::ObjectDriver::DBI added to 
	 implement DBI-level database connection caching.  
	 Helios::Service, Helios::Logger, and Helios::Job and 
	 have been changed to use the new connection handling scheme.
	-Changed Bundle::Helios::Generic to Bundle::Helios (since the 
	 RedHat-specific bundle has been eliminated). added worker_blitz_factor configuration parameter to 
	 allow MAX_WORKERS workers to launch before there are that many 
	 jobs available in the job queue.
2.41  Sun Jun 03 22:00:00 2012
	-Official Oracle support!  DDL for a Helios Oracle schema is in 
	 'sql/helios_schema_oracle.sql'.  Please note: 
	 1) you will need to adjust the Oracle schema to fit your 
	    environment (especially in regards to security and tablespaces)
	 2) while the Helios core supports Oracle, the Helios::Panoptes 
	    web admin interface still only supports MySQL (Panoptes 
	    support for Oracle is being worked on) 
	-Helios::Service and Helios::Job: added deferredJob() and 
	 deferred() methods to defer processing of a job even though it 
	 was available in the job queue.  These methods (for now) simply 
	 expose the declined() feature added in TheSchwartz 1.10; no Helios
	 job history is recorded for a deferred job.  Existing Helios 
	 users will need to upgrade their TheSchwartz library to 1.10 to 
	 use this feature.
	-Helios::Logger & Helios::Logger::Internal:  moved driver 
	 creation to base Helios::Logger class so (if necessary) any 
	 loggers can get a Data::ObjectDriver to the collective database
	-Helios::Service & Helios::Logger:  refactored getDriver() into 
	 initDriver() and getDriver() to eventually allow caching of 
	 Data::ObjectDriver objects.  Anything needing an ObjectDriver to 
	 the collective database should just continue to call getDriver() 
	 and everything will work fine. calls the service class prep() method on startup 
	 rather than getConfigFromIni() and getConfigFromDb() separately.
	 This ensures proper setup of the loggers and Data::ObjectDriver 
	 db connection. changed startup message so perl doesn't carp a warning 
	 if the service class doesn't have a $VERSION defined. added registration_interval as a configuration 
	 parameter (previously it was hard-coded to 300 seconds in  The "registration_interval" parameter is the amount 
	 of time (in secs) between service daemon "collective check-ins" 
	 (when a service daemon records its current status in the 
	 HELIOS_WORKER_REGISTRY_TB table).  This table is used to create 
	 the Helios::Panoptes Collective Admin page, and is also useful 
	 for system monitoring and statistics. set new defaults for zero_sleep_interval (10) and 
	 registration_interval (60).  These new defaults should make 
	 Helios more responsive in low load situations and generally work 
	 better for more users out-of-the-box.  (The old defaults geared 
	 Helios more for large volumes of long-running jobs on heavily
	 loaded databases.  The new defaults should work for a better 
	 range of small- to mid-sized loads.)  If these new defaults 
	 create too much traffic for your database, you can set new 
	 larger values in your helios.ini file to decrease database 
	 traffic. changes to prevent a worker from transmuting to a new 
	 service daemon (caused by database instability during transition 
	 between, TheSchwartz->work(), and Helios::Service->work() 
	-updated tests  fixed example in POD
	-Removed Bundle::Helios::RedHat.  Ultimately, it didn't work any 
	 better (or worse) than using 'install Helios' command with the 
	 CPAN shell.  Bundle::Helios::Generic seems to work well on other 
	 platforms, however.  If you wish to use Helios with RHEL/CentOS 
	 5.x or earlier, it is recommended you install a more recent 
	 version of Perl than 5.8.8 for ease of installation reasons.  
2.40  Sun Jan 22 22:30:00 2012
	-NEW Extensible logging subsystem (Helios::Logger) 
	-NEW Helios::Error::BaseError exception class; acts as parent for
	 entire Helios::Error:: hierarchy
	-NEW Helios::Service->metarun() method to modularize metajob 
	 handling and provide for extensible metajob support 
	-NEW service run() and metarun() methods now run in an eval 
	 block as a process safety measure to catch uncaught exceptions.
	-NEW MP3IndexerService example application including in eg/
	 directory (StubService also rewritten for clarity)
	-REVISED Helios::Service->work() method no longer pays attention 
	 to return value of run() method (this feature was under-
	 documented, misunderstood, and caused problems with eval {} and 
	 Try::Tiny exception handling
	-REWRITTEN CGI script; supports sending XML stream 
	 in addition to form encoding, no longer dependent on 
	-REWRITTEN Helios::TestService; more modern Perl and easier to 
	-REWRITTEN install instructions, including specific instructions 
	 for Red Hat- and Ubuntu-based systems, and including CPAN install 
     bundles (still experimental)
    -REWRITTEN Helios::Tutorial 
    -Helios::Service:  fixed MaxRetries() and RetryInterval() retry 
     job methods
	-Helios::Job:  changed failed() and failedNoRetry() to limit the 
	 char length of the error recorded to 254 chars.  That's one less 
	 than the default size of the db field in the ERROR table, so it 
	 should prevent long errors like stack traces from unexpectedly 
	 blowing up worker processes and potentially losing jobs.
	-Revised dependencies:
	 DBI 1.52 (shipped with RHEL/CentOS 5)
	 XML::Simple 2.14 (shipped with RHEL/CentOS 5)
	 Removed XML::SAX dependency (unnecessary)
	 Removed XML::Namespace dependency (unnecessary)
	 Removed XML::Parser dependency (unnecessary)
	-Removed deprecated classes, methods, and other files:
	 Helios::Service->parseArgXML() (deprecated since 2.00)
	 Helios::Worker (deprecated since 2.00)
	-Updated copyright notices
	-Switch to "Linux-style" versioning: 
	 odd minor version == development version
	 even minor version == stable version
	 second minor number == patch level
	 (we're still also using Perl-style _ for devel versions too)
2.23  Fri Sep 10 12:22:00 2010
	-Helios::Job: fixed bug where getArgXML() returned undef if job
	 object was vivified from job queue
2.22  Thu May 21 11:30:00 2009
	-Helios::Service: fixed a bug in getFuncidFromDb() that caused 
	 services to fail to load properly if there was no entry for them 
	 in FUNCMAP table. Several revisions to make it a more robust daemon. Now
	 honors TERM signal; 'kill <pid>' from a shell will attempt to 
	 safely shut down workers and daemon process w/o using Panoptes
	-Documentation updates
2.21  Thu May 14 17:00:00 2009
	-added set/getJob() accessors to facilitate access to current 
	 Helios::Job object from methods other than run()
2.20  Tue Apr 28 18:00:00 2009
    -various tweaks for cross-platform compatibility
    -documentation additions/corrections
    -added Helios::LogEntry::Levels to remove dependencies on 
     Sys::Syslog Cleaned up messages to console after daemonize + Helios::Service: added support for WORKER_MAX_TTL 
	 config param
    -Helios::Service: added JobClass() allow extensible Helios::Job 
    -Helios::Service: added MaxRetries() and RetryInterval() to replace
     TheSchwartz's max_retries() and retry_interval() (this is not an 
     abitrary change; it's to allow for extensions at the Helios layer 
     in the future)
    -Helios::Service: added default run() method for class completeness
     (it throws a Helios::Error::FatalNoRetry error because you forgot 
     to implement a run() method)
    -Helios::Service: removed logging to syslogd to eliminate 
     Sys::Syslog dependency (see HeliosX::ExtLoggerService)
    -Helios::Service: added set/getFuncid(), getFuncidFromDb() and 
     changed jobWaiting() to use them.  This eliminates an unnecessary 
     database query previously done every time jobsWaiting() was called
    -Helios::Service: added support for log_priority_threshold config 
    -Helios::Job: added getFailures() to access the number of times a 
     job has previously failed
2.00  Fri Aug 01 02:00:00 2008
	-First public production release (same as 1.90_26 w/more documentation)
1.90_26 Thu Jun 26 11:30:00 2008
	-Helios 2.0 RC1
	-NEW Helios 2.0 API
	 Helios::TestService added PID check to prevent 2 instances of a service 
	 running on the same server added --clear-halt option to clear Worker Admin HALTs 
	 at the cmd line
	-helios.sql: new helios_worker_registry_tb.start_time field for 
	 uptime stats,, use new 
	 2.0 API
	-eg/Stub/ for example of new 2.0 API service class
	-new tests to test both 1.x and 2.x API	
1.19_07 Thu May 29 14:00:00 2008
	-added (for version checking & documentation)
	-added Helios::Job (for eventual refactoring)
	-added Helios::Test (for system testing)
1.19_06 Wed May 28 12:00:00 2008
	-added LICENSE file that was left out
	-add utility to clean log, job history
	-added eg/Stub/ as a worker class stub example
1.19  Mon May 19 12:00:00 2008
	-First public release