After upgrading to AIX 5.3 TL9 SP4, we found that secldapclntd will go into a death loop during a HACMP failover. It consumes more and more CPU until the system doesn’t have any capacity left, and stops the HACMP failover. Killing secldapclntd will let HACMP continue.

We didn’t see this behavior w/ AIX 5.3 TL8 SP3. IBM has identified a couple of issues that are probably coming together to cause our problem, but they won’t be fixed in TL9… ever. IBM’s work-around is to setup a pre and post-event script to stop secldapclntd before the IP takeover (and release) and restart it afterward. In testing, this works pretty well, and it only takes a few seconds to stop and start secldapclntd.

Here’s the workaround by IBM:

1. Create a script “/usr/local/cluster/start-ldap.sh” and copy it to every node in the cluster

#!/usr/bin/ksh
echo “STOP LDAP CLIENT Daemon”
/usr/sbin/start-secldapclntd
exit 0

2. Create a script “/usr/local/cluster/stop-ldap.sh” and copy it to every node in the cluster

#!/usr/bin/ksh
echo “STOP LDAP CLIENT Daemon”
/usr/sbin/stop-secldapclntd
exit 0

3. Create a pre-event

smitty hacmp
Extended Configuration
Extended Event Configuration
Configure Pre/Post-Event Commands
Add a Custom Cluster Event

Type or select values in entry fields.
Press Enter AFTER making all desired changes.
[Entry Fields]

* Cluster Event Name [] << I use the name "ldapClientStart" * Cluster Event Description [] << Start ldap client daemon * Cluster Event Script Filename [] << /usr/local/cluster/start-ldap.sh

4. Create a post-event

smitty hacmp
Extended Configuration
Extended Event Configuration
Configure Pre/Post-Event Commands
Add a Custom Cluster Event

Type or select values in entry fields.
Press Enter AFTER making all desired changes.
[Entry Fields]

* Cluster Event Name [] << I use the name "ldapClientStop" * Cluster Event Description [] << Stop ldap client daemon * Cluster Event Script Filename [] << /usr/local/cluster/stop-ldap.sh

5. Update the acquire_service_addr event

smitty hacmp
Extended Configuration
Extended Event Configuration
Change/Show Pre-Defined HACMP Events
(select –> acquire_service_addr )
Change/Show Cluster Events

Type or select values in entry fields.
Press Enter AFTER making all desired changes.
[Entry Fields]

Event Name acquire_service_addr
Pre-event Command [ldapClientStop] <<< the defined name "ldapClientStop" Post-event Command [ldapClientStart] <<< the defined name "ldapClientStart"

6. Update the release_service_addr event

smitty hacmp
Extended Configuration
Extended Event Configuration
Change/Show Pre-Defined HACMP Events
(select –> release_service_addr )
Change/Show Cluster Events

Type or select values in entry fields.
Press Enter AFTER making all desired changes.
[Entry Fields]

Event Name release_service_addr
Pre-event Command [ldapClientStop] <<< the defined name "ldapClientStop" Post-event Command [ldapClientStart] <<< the defined name "ldapClientStart"

7. Synchronize the cluster configuration, and you’re done

After upgrading to AIX 5.3 TL9 SP4, we found that secldapclntd will go into a death loop during a HACMP failover. It consumes more and more CPU until the system doesn’t have any capacity left, and stops the HACMP failover. Killing secldapclntd will let HACMP continue.<\/p>\n

We didn’t see this behavior w\/ AIX 5.3 TL8 SP3. IBM has identified a couple of issues that are probably coming together to cause our problem, but they won’t be fixed in TL9… ever. IBM’s work-around is to setup a pre and post-event script to stop secldapclntd before the IP takeover (and release) and restart it afterward. In testing, this works pretty well, and it only takes a few seconds to stop and start secldapclntd.<\/p>\n

Here’s the workaround by IBM:<\/p>\n

\n
1. Create a script “\/usr\/local\/cluster\/start-ldap.sh” and copy it to every node in the cluster<\/li>\n

   #!\/usr\/bin\/ksh
   \necho “STOP LDAP CLIENT Daemon”
   \n\/usr\/sbin\/start-secldapclntd
   \nexit 0<\/p>\n

2. Create a script “\/usr\/local\/cluster\/stop-ldap.sh” and copy it to every node in the cluster<\/li>\n

   #!\/usr\/bin\/ksh
   \necho “STOP LDAP CLIENT Daemon”
   \n\/usr\/sbin\/stop-secldapclntd
   \nexit 0\n<\/p>\n

3. Create a pre-event<\/li>\n

   smitty hacmp
   \nExtended Configuration
   \nExtended Event Configuration
   \nConfigure Pre\/Post-Event Commands
   \nAdd a Custom Cluster Event<\/p>\n

   Type or select values in entry fields.
   \nPress Enter AFTER making all desired changes.
   \n[Entry Fields]<\/p>\n

   * Cluster Event Name [] << I use the name \"ldapClientStart\"\n * Cluster Event Description [] << Start ldap client daemon\n * Cluster Event Script Filename [] << \/usr\/local\/cluster\/start-ldap.sh\n<\/p>\n

4. Create a post-event<\/li>\n

   smitty hacmp
   \nExtended Configuration
   \nExtended Event Configuration
   \nConfigure Pre\/Post-Event Commands
   \nAdd a Custom Cluster Event<\/p>\n

   Type or select values in entry fields.
   \nPress Enter AFTER making all desired changes.
   \n[Entry Fields]<\/p>\n

   * Cluster Event Name [] << I use the name \"ldapClientStop\"\n * Cluster Event Description [] << Stop ldap client daemon\n * Cluster Event Script Filename [] << \/usr\/local\/cluster\/stop-ldap.sh \n<\/p>\n

5. Update the acquire_service_addr event<\/li>\n

   smitty hacmp
   \nExtended Configuration
   \nExtended Event Configuration
   \nChange\/Show Pre-Defined HACMP Events
   \n(select –> acquire_service_addr )
   \nChange\/Show Cluster Events<\/p>\n

   Type or select values in entry fields.
   \nPress Enter AFTER making all desired changes.
   \n[Entry Fields]<\/p>\n

   Event Name acquire_service_addr
   \nPre-event Command [ldapClientStop] <<< the defined name \"ldapClientStop\"\nPost-event Command [ldapClientStart] <<< the defined name \"ldapClientStart\"<\/p>\n

6. Update the release_service_addr event<\/li>\n

   smitty hacmp
   \nExtended Configuration
   \nExtended Event Configuration
   \nChange\/Show Pre-Defined HACMP Events
   \n(select –> release_service_addr )
   \nChange\/Show Cluster Events<\/p>\n

   Type or select values in entry fields.
   \nPress Enter AFTER making all desired changes.
   \n[Entry Fields]<\/p>\n

   Event Name release_service_addr
   \nPre-event Command [ldapClientStop] <<< the defined name \"ldapClientStop\"\nPost-event Command [ldapClientStart] <<< the defined name \"ldapClientStart\"<\/p>\n

7. Synchronize the cluster configuration, and you’re done<\/li>\n<\/ol>\n","protected":false},"excerpt":{"rendered":null,"protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2,3,1],"tags":[],"class_list":["post-402","post","type-post","status-publish","format-standard","hentry","category-aix-notes","category-hacmp-notes","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/rootuser.ninja\/index.php\/wp-json\/wp\/v2\/posts\/402","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/rootuser.ninja\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/rootuser.ninja\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/rootuser.ninja\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/rootuser.ninja\/index.php\/wp-json\/wp\/v2\/comments?post=402"}],"version-history":[{"count":0,"href":"https:\/\/rootuser.ninja\/index.php\/wp-json\/wp\/v2\/posts\/402\/revisions"}],"wp:attachment":[{"href":"https:\/\/rootuser.ninja\/index.php\/wp-json\/wp\/v2\/media?parent=402"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/rootuser.ninja\/index.php\/wp-json\/wp\/v2\/categories?post=402"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/rootuser.ninja\/index.php\/wp-json\/wp\/v2\/tags?post=402"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}