IT17678: SWITCH ALERTS - ISSUE WITH BROCADE TRUNKED ISLS, BUFFER CREDITS GETTING CLOSE TO ZERO.

IBM Spectrum Control V5.2.13 (March 2017)
IBM Spectrum Control V5.2.14 (May 2017)
IBM Spectrum Control V5.2.15 (August 2017)
IBM Spectrum Control V5.2.15.2 (November 2017)
IBM Spectrum Control V5.2.16 (March 2018)
IBM Spectrum Control V5.2.17 (May 2018)

APAR status

• Closed as program error.

Error description

• IBM Spectrum Control has problems with the behavior of the
  Brocade ISL (inter-switch links), a.k.a "trunks", with regard to
  workload and buffer credits.
  The Brocade switch monitoring code needs to be adjusted with
  regards to the way that the buffer credits near zero are
  aggregated from ports to trunks, to avoid constantly showing
  large BCZ counts for the trunks.
  RECREATE STEPS:
  Monitor Brocade switch environments and notice a large number of
  critical threshold violations.
  ________________________________________________________________
  DB2 Version used for Server:    N/A
  The defect is against component:   5608TPC00
  Server/Manager build/release (TPC):   5.2.8
  ________________________________________________________________
  Problem as described by customer:  Large number of
  CriticalThreshold Violations on SAN ISL links describing "Zero
  Buffer Credit Count".
  Initial customer impact (low/med/high):  med
  

Local fix

• apply fixing ptf when available.
  

Problem summary

• ****************************************************************
  * USERS AFFECTED:                                              *
  * IBM Spectrum Control 5.2.x users monitoring Brocade fabrics  *
  * with ISL (inter-switch links)                                *
  ****************************************************************
  * PROBLEM DESCRIPTION:                                         *
  * IBM Spectrum Control has problems with the behavior of the   *
  * Brocade ISL (inter-switch links) "trunks", with regard to    *
  * workload and buffer credits.  Spectrum Control users         *
  * monitoring Brocade fabrics with ISL may encounter a large    *
  * number of Critical Threshold Violations on SAN ISL links     *
  * describing "Zero Buffer Credit Count".                       *
  ****************************************************************
  * RECOMMENDATION:                                              *
  * Apply fix maintenance when available                         *
  ****************************************************************
  

Problem conclusion

• The fix for this APAR is targeted for the following maintenance
  package:
  
  | refresh pack | 5.2-TIV-TPC-RP0013 - target March 2017
  
  Fixed in IBM Spectrum Control 5.2.13
  
  http://www.ibm.com/support/docview.wss?&uid=swg21320822
  
  The target dates for future refresh packs do not represent a
  formal commitment by IBM. The dates are subject to change
  without notice.
  

Temporary fix

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

Modules/Macros

• FABRIC
  

Fix information

• Fixed component name

  TPC ADVANCED

• Fixed component ID

  5608TPCA0

Applicable component levels