OpenVMS VAXCLIU01_072 VAX V7.2 CLUSTER ECO Summary
TITLE: OpenVMS VAXCLIU01_072 VAX V7.2 CLUSTER ECO Summary
New Kit Date : 09-MAY-2001
Modification Date: Not Applicable
Modification Type: New Kit
NOTE: An OpenVMS saveset or PCSI installation file is stored
on the Internet in a self-expanding compressed file.
For OpenVMS savesets, the name of the compressed saveset
file will be kit_name.a-dcx_vaxexe for OpenVMS VAX or
kit_name.a-dcx_axpexe for OpenVMS Alpha. Once the OpenVMS
saveset is copied to your system, expand the compressed
saveset by typing RUN kitname.dcx_vaxexe or kitname.dcx_alpexe.
For PCSI files, once the PCSI file is copied to your system,
rename the PCSI file to kitname-dcx_axpexe.pcsi, then it can
be expanded by typing RUN kitname-dcx_axpexe.pcsi. The resultant
file will be the PCSI installation file which can be used to install
the ECO.
Copyright (c) Compaq Computer Corporation 2001. All rights reserved.
OP/SYS: OpenVMS VAX
COMPONENT: CLUSTER
SOURCE: Compaq Computer Corporation
ECO INFORMATION:
ECO Kit Name: VAXCLIU01_072
ECO Kits Superseded by This ECO Kit: None
ECO Kit Approximate Size: 1350 Blocks
Kit Applies To: OpenVMS VAX V7.2
System/Cluster Reboot Necessary: YES
Rolling Re-boot Supported: YES
Installation Rating: INSTALL_3
3 - To be installed on all systems running
the listed versions of OpenVMS which
are experiencing the problems described.
Kit Dependencies:
The following remedial kit(s) must be installed BEFORE
installation of this kit:
VAXUPDATE01_072
VAXRMS01_072
In order to receive all the corrections listed in this
kit, the following remedial kits should also be installed:
None
ECO KIT SUMMARY:
An ECO kit exists for CLUSTER on OpenVMS VAX V7.2. This kit addresses
the following problems:
o A new /SHARE qualifier has been added to the SET FILE command.
This qualifier allows you to enable or disable global buffers
or statistics on a file currently being accessed by other
users. Only new accessors of the file will acquire the new
settings. This qualifier requires SYSPRV (system privilege).
The /SHARE qualifier is only valid with the following
qualifiers:
/[NO]GLOBAL_BUFFER=count/SHARE
/[NO]STATISTICS/SHARE
If other qualifiers are needed, they must be entered in a
separate SET FILE command.
/[NO]GLOBAL_BUFFER=count/SHARE
The /SHARE qualifier can be used to enable or disable global
buffers on a file currently being accessed. However, any new
global buffer settings will only be applied to new accessors
of the file. And if a file is already opened with global
buffers, any new number of global buffers will not take effect
until the file is closed by all accessors of the file.
/[NO]STATISTICS/SHARE
The /SHARE qualifier can be used to enable or disable
statistics on a file currently being accessed. However, only
statistics of new accessors of the file will be measured.
EXAMPLE:
$ SET FILE/SHARE/GLOBAL_BUFFER=5000/STATISTICS INVENTORY.IDX
This example sets 5000 global buffers on the INVENTORY.IDX
file and enables statistics. Without the /SHARE qualifier, if
the file was open when the SET FILE command was issued, the
following error would be returned: SYSTEM-W-ACCONFLICT (file
access conflict). The /SHARE qualifier allows the global
buffers and statistics to be enabled on an open file.
However, these settings only apply to new
Images Affected: [SYSEXE]SET.EXE
[SYSLIB]DCLTABLES.EXE (SET.CLD replaced)
o New qualifier /CONTENTION_POLICY added to SET RMS_DEFAULT (and
SHOW RMS_DEFAULT display) to address locking fairness issues.
The new Alpha global buffer read-mode lock support introduced
in V7.2-1H1 is functionally compatible with both VAX and older
Alpha releases. Operations in mixed clusters produce correct
results. However, there is a locking fairness issue that may
arise with mixed cluster operations.
In a mixed cluster environment with very high contention for
specific buckets, it is possible for accesses to write-shared
files on nodes using read-mode bucket locking to dominate
access to a bucket. Nodes without this support might be
unable to access the bucket for a protracted period of time.
It is also possible to observe comparable behavior on all
OpenVMS versions when dealing with accesses to write-shared
files without global buffers enabled -- even on a standalone
system. A similar fairness issue between lock conversions and
new lock requests may be observed in which the new lock
requests may remain ungranted for an extended period of time.
This kit provides an interface for RMS support for a new
option to improve fairness under high contention conditions
for write-shared files. The option is controlled using the
/CONTENTION_POLICY qualifier to the DCL command SET
RMS_DEFAULT. The option may be set at a process or system
level. Since selecting this option may noticably increase
locking overhead and since many applications will never
encounter this issue, the default system behavior leaves this
option disabled. A future lock management enhancement should
make this fairness workaround unnecessary for later releases.
The following are valid PROCESS keywords (/SYSTEM not
specified) for SET RMS_DEFAULT/CONTENTION_POLICY:
NEVER Never use the higher overhead option
to improve fairness for any write-shared
files accessed by this process;
minimal overhead.
SOMETIMES Use this option for fairer bucket
access (but higher overhead) to any
write-shared files with global
buffers enabled that are accessed by this
process.
ALWAYS Use this option for fairer bucket
access (but higher overhead) to all
write-shared files accessed by this
process.
The following are valid SYSTEM keywords (/SYSTEM specified):
NEVER (Default) Never use the higher
overhead option to improve fairness
for any write-shared files accessed
on the system; minimal overhead.
SOMETIMES Use this option for fairer bucket
access (but higher overhead) to any
write-shared files with global
buffers enabled that are accessed
on the system.
ALWAYS Use this option for fairer bucket
access (but higher overhead) to all
write-shared files accessed on the
system.
Images Affected: [SYSEXE]SET.EXE
[SYSEXE]SHOW.EXE
[SYSMSG]CLIUTLMSG.EXE
[SYSLIB]DCLTABLES.EXE (SET.CLD replaced)
o When access is attempted on a QUE object to which the subject
account does nothave the appropriate privilege, the ensuing
audit record does not record the access failure.
Images Affected: [SYSEXE]SUBMIT.EXE
o A DCL "$ SHOW CLUSTER" command will hang on startup, on
cluster-nodes with many SCS-ports (CIPCA, CIXCD, MC:... Pxx0:
devices), if the virtual-circuit (PB$ path-block) count
exceeds the SCS-node count X 4. An "SCS-node" is defined as
any SCS-speaking node, such as HSJxx/HSCxx Storage
Controllers, RFxx DSSI disk-controllers, VMS nodes, etc.
Images Affected: [SYSEXE]SHWCLSTR.EXE
INSTALLATION NOTES:
This kit requires a system reboot. Compaq strongly recommends that
a reboot is performed immediately after kit installation to avoid
system instability
If you have other nodes in your OpenVMS cluster, they must also be
rebooted in order to make use of the new image(s). If it is not
possible or convenient to reboot the entire cluster at this time, a
rolling re-boot may be performed.
All trademarks are the property of their respective owners.
This patch can be found at any of these sites:
Colorado Site
Georgia Site
Files on this server are as follows:
vaxcliu01_072.README
vaxcliu01_072.CHKSUM
vaxcliu01_072.CVRLET_TXT
vaxcliu01_072.a-dcx_vaxexe
vaxcliu01_072.CVRLET_TXT
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