EMS Manual

Configuring EMS
EMS Manual—426909-005
12-20
Reliability
Reliability
Almost all EMS processes run as process pairs, reducing the possibility that a single-
component failure can cause a process to fail. A primary collector always runs as a
process pair; an alternate collector can run as a process pair; a compatibility distributor
runs as a process pair if it is initiated by a system load or by a RUN command with the
BACKUP parameter included. A consumer, printing, or forwarding distributor runs as a
process pair if you include the BACKUP parameter in the RUN command. The EMF
(EMS filter) language compiler and the various interactive utility programs do not run
as process pairs.
Resources
Several logging options control the amount of disk space a collector can use. To
conserve disk space, set MAXFILE, PRIMARYEXTENTS, or SECONDARYEXTENTS
to a low value. But a smaller log fills faster, requiring you to archive and purge the log
files more rapidly, or to set ROTATEFILES to TRUE and let the collector overwrite older
event messages.
Using filters in collectors can also reduce the amount of disk space needed to store
events.
To reduce the number of EMS processes, use the multiple-source and (in some cases)
multiple-destination features of the distributors. For example, if you need two copies of
the event-message text, you can run two printing distributors or, as long as it is
acceptable for both destinations to receive identical output, you can run one printing
distributor to two destinations.
For a description of strategies for reducing consumption of network resources and for
logging to remote nodes when the logging resources on the local node are restricted,
see Networking Considerations
on page 12-16.
Security
Two log file attributes relate to security:

PROTECTION specifies the read-write-execute-purge file security assigned to
each log file when it is created.

DISCACCESSID specifies the user ID that a collector uses when accessing its log
files.
Similar to security for a file, you should set the PROTECTION attribute according to
your requirements for protecting confidential information, allowing access to
appropriate users while preventing accidental purging of important files.
The primary collector DISCACCESSID attribute defaults to SUPER.SUPER. If a
SUPER.SUPER user does not have access to files on a node where you want to place
log files, you must change DISCACCESSID to a user ID that does have access to files
on that node. For security reasons, the value of DISCACCESSID is not returned when
collector status is requested, and the value is not saved across system loads.