CONTROL-M vs. CRON - BMC Communities - BMC Software

CONTROL-M ®
vs. CRON

Contents
Introduction.....................................................................................................1
Architecture ....................................................................................................1
Reliability, Availability and Scalability .........................................................3
Focal Point of Control....................................................................................3
Management-by-Exception............................................................................4
Comprehensive Scheduling ..........................................................................5
Open Load Balancing.....................................................................................6

Introduction
Architecture
CONTROL-M is BMC Software’s enterprise-wide management solution designed to
automate heterogeneous production environments. As data center complexity grows,
CONTROL-M consolidates and integrates the hardware and software networks across
the organization.
While CRON is only a built-in Unix-based scheduler, CONTROL-M provides
comprehensive production management for the entire enterprise. CONTROL-M
offers production control and scheduling capabilities across multiple platforms,
including MVS, Unix, Microsoft Windows NT, VMS, OS/400, Tandem and OS/2.
CONTROL-M is tightly integrated with ERP applications and frameworks. These
applications can be efficiently integrated into the production environment. Users can
manage application jobs without adding new tools or methods. CONTROL-M has
certified interfaces to SAP R/3, Oracle Applications, Baan and PeopleSoft.
CONTROL-M
CONTROL-M provides a three-tier architecture to support configurations driven by
business requirements, not technology limitations. This architecture provides the
capability to control an unlimited number of systems, overcoming the constraints of
managing a wide array of platforms, applications and interfaces. The three-tier
architecture consists of Enterprise Controlstation ®
, CONTROL-M/Servers and
CONTROL-M/Agents.
Enterprise Controlstation supplies a GUI offering a unified interface to all platforms, easily
managing cross-platform dependencies. This consolidated view of scheduling
information, active job information and exceptions enables control over the production
environment. Thus, businesses eliminate the need for platform-specific experts and
cross-training.
CONTROL-M/Server is a full-function scheduler available on over 20 platforms. Each
CONTROL-M/Server maintains its own database containing the relevant scheduling
information for all agents connected to the CONTROL-M/Server. The information from
the servers is communicated to the Enterprise Controlstation for inclusion in the consolidated
view.
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CONTROL-M is part of a three-tier architecture that supports configurations driven by business requirements, not
technology limitations.
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CONTROL-M/Agents are managed by a CONTROL-M/Server. These
CONTROL-M/Agents provide job submission, tracking and result analysis.
Thus, CONTROL-M/Agents eliminate the need for a local database and additional
administration, since scheduling decisions are made by the CONTROL-M/Server
and transferred to the agent for execution.
CRON
CRON is a single-tier scheduler that operates on Unix machines. The use of single-tier
technology guarantees high availability, since each exceptional situation affects only
the system experiencing the problem. Neither the network nor another system has to
run the schedule on any specific machine.
The downside of this system is that dependencies spanning more than one box cannot
be managed by the CRON scheduling tool, since each box is operating as a stand-alone
system. When an application requires a dependency, an external mechanism must be
used. Such mechanisms are usually developed and maintained by the user. Therefore,
the results of single-tier architecture are high administrative overhead and reduced system
reliability.
Additionally, with single-tier products there is no way to view and monitor the entire
environment. A box is stand-alone, and the user must log on to each box to determine
its schedule status.

Reliability, Availability and Scalability
CONTROL-M
Enterprise Controlstation and CONTROL-M offer a reliable and productive real-time
environment where users can monitor the entire network. The Enterprise Controlstation
GUI displays comprehensive data from every CONTROL-M/Server, eliminating the
need to track production events manually.
Enterprise Controlstation and CONTROL-M/Server communicate through gateway
software. Therefore, in cases of communication failure, both the CONTROL-M and
the Enterprise Controlstation database continue to gather information to guarantee
data integrity. When communication is reestablished, the databases are automatically
synchronized. Additionally, each CONTROL-M/Server contains fail-over capabilities
to handle recovery in the event of problems.
The CONTROL-M architecture enables growth and adaptation to changing environments.
Flexible configurations are supported and components can reside on one or more physical
hosts. This adaptability eliminates bottlenecks, ensuring optimal performance for highvolume
workloads.
CRON
Data integrity relies on the availability of the machine on which CRON is running. If the
job definition files are corrupted, there is no easy method for recovery.
Additionally, CRON has the following drawbacks:
• The production scheduler must reside on each platform. Therefore, the configuration is
not flexible.
• Each new application must be added manually to every platform.
• There is no central repository for the information existing on the platforms.
• A box is stand-alone, and the user has to log on to each box to define and track jobs.
Focal Point of Control
CONTROL-M
Enterprise Controlstation overcomes platform challenges while integrating the expertise
of data center personnel and automated processes. The product automatically translates
platform-specific data, making it unnecessary for data center users to handle
this information manually.
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The growing number of data center systems and platforms compounds the number of
critical situations encountered. CONTROL-M meets the challenge of handling all adverse
situations, scheduling modifications and execution bottlenecks.
Enterprise Controlstation automates and unifies task relationships, error and problem
correction, tracking and outcome verification. Businesses can then eliminate the cost and
impact on productivity caused by training personnel on specific platforms. Additionally,
the production workflow is not at risk when organizational changes occur or key personnel
are absent.
CRON
CRON is based on Unix command lines. It is therefore necessary to train specific staff
members about the use of various Unix operating systems.
Tasks and events on each platform have to be controlled and monitored individually.
This is a very complicated job, especially when dealing with large environments. Since
there are no common event-management tools, manual errors occur often and events
are overlooked.
In some cases, a front-end allows the user to switch between different windows displaying
various systems. However, these front-ends are no more than “face lifts”; the user still has
to move from window to window and does not receive a unified view of the entire production
environment.
Management-by-Exception
CONTROL-M
Enterprise Controlstation operates on the management-by-exception principle. The
product has a unique user notification facility, the Alert window, which accumulates
and displays SHOUT messages from each CONTROL-M installation. CONTROL-M
can send these SHOUT messages to interactive users, SNMP traps and event
management systems (such as PATROL ®
by BMC Software).
CRON
Users have to track jobs proactively, manually searching for exception events. To keep
the production environment active at all times, much time and effort must be put into
identifying and handling problems, making production slow and costly.

Comprehensive Scheduling
CONTROL-M
Common definition interface
CONTROL-M’s single-definition facility uses point-and-click and drag-and-drop functions
in combination with a flexible fill-in-the-blanks approach. Each task is defined using
a single window. New definitions are easily created through a predefined outline. Several
jobs can be defined according to the same outline, and mass updates can be used to change
the relevant fields for several jobs in a single action. CONTROL-M provides a consistent
task-definition process regardless of the platform.
The Enterprise Controlstation Windows NT GUI allows users to intuitively create and
maintain scheduling definitions. Dependencies can be drawn between relevant jobs.
Additionally, global job updates and creations can be performed and the jobs are then
arranged graphically. The Windows NT GUI allows users to view the job flow during
the definition stage. It is therefore possible to eliminate loops and verify that the correct
job flow has been created.
Scheduling capabilities
CONTROL-M can handle the most complex scheduling scenarios while reducing
maintenance resulting from constant growth and changes in the production environment.
Users can define scheduling references common to many tasks. For example, it is
possible to define calendars that represent holidays or work periods for the organization.
These calendars can then be used by several jobs.
Dynamic parameter modification
The CONTROL-M AutoEdit feature is an automatic setup facility that handles batch
process modifications. The AutoEdit facility can handle even the most complex situations.
The AutoEdit facility can perform tasks such as simple expression and calculation assignment,
and comparison of values. Before CONTROL-M submits a task, the product analyzes
and passes the resulting values to the AutoEdit script.
External event management
External events such as file events are coordinated using CONTROL-M tasks. Additionally,
CONTROL-M provides full support for ad hoc tasks. When an unplanned task is
to be submitted, the product manages the task in the same way that regularly scheduled
tasks are managed.
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Result processing
CONTROL-M identifies and handles every combination of post-processing situations,
including system crashes, security violations and execution errors. The product dynamically
improves productivity by automatically detecting and managing all possible production
situations as they occur.
CRON
Job definitions in CRON require detailed knowledge of Unix in general and scripting
specifically. Users must employ Unix editing tools (most commonly “vi”) to create job
definitions.
There is no graphical tool to view the job definitions. Therefore, the only way to be
certain that the flow is correct is to submit a job definition and then correct the resulting
errors. Each job is defined separately. When updates need to be made, only one job
definition can be edited at a time.
Since it is not possible to perform advanced error handling through CRON, users manually
manipulate code in order to handle potential events. This causes a large amount of maintenance
overhead.
Open Load Balancing
CONTROL-M
Through the three-tier architecture and server/agent technology, CONTROL-M allows
users to perform resource monitoring for agent platforms distributed across the network.
CONTROL-M submits tasks to the agent platform with sufficient available resources to
handle the execution. Thus, the product achieves optimum production throughput.
By supplying monitoring and balancing tools, CONTROL-M prevents destructive
execution bottlenecks. A task is released only when all required resources are available.
This prevents resource queuing while allowing for application control. CONTROL-M
improves overall system throughput by eliminating the need for manual resource management
and control.
CRON
CRON has a single-tier architecture. Therefore, each scheduler must reside on its own
machine and contain its own database. Since there is no integration between the schedulers
on the various machines, it is not possible to transfer jobs from one machine to the
other, even if one machine has a heavy workload.

About BMC Software
BMC Software is the world’s leading provider of management solutions that ensure the
availability, performance and recovery of companies’ business-critical applications. We
call this application service assurance
, and it means the applications you and your customers
rely on most stay up and running around the clock. For more than 19 years, the
world’s leading companies have relied on BMC Software.
BMC Software is among the world’s largest independent software vendors, is a Forbes
500 company and is a member of the S&P 500, with fiscal year 1999 revenues exceeding
$1.3 billion. The company is headquartered in Houston, Texas, with offices worldwide.
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