High cpu utilization in host domain from MGWD in ONTAP 9.7

Applies to

• ONTAP 9.7 - 9.7P7
• Intercluster LIF
• MGWD
• HostOS CPU domain

Issue

• Increased CPU Utilization due to host domain in ONTAP 9.7

Example: sysstat -M output showing high Host domain activity (some columns removed for readibility):

Cluster::> set diag -c off; node run -node Cluster1-01 sysstat -M 1
ANY1+ ANY2+ ANY3+ ANY4+  AVG CPU0 CPU1 CPU2 CPU3 Host  
 100%   52%   33%   18%  51%  61%  54%  46%  42% 179%  
 100%   60%   38%   21%  55%  63%  58%  51%  48% 179%  
 100%   59%   39%   22%  55%  63%  58%  52%  48% 175%  
 100%   61%   40%   23%  56%  63%  58%  54%  49% 181%  
 100%   58%   38%   21%  54%  63%  55%  51%  48% 177%  
 100%   55%   35%   20%  53%  62%  54%  50%  44% 180%  
 100%   54%   33%   18%  51%  61%  53%  49%  44% 179%  
 100%   46%   29%   14%  47%  59%  51%  42%  37% 179%  
 100%   50%   31%   16%  49%  61%  49%  48%  39% 176%  
 100%   47%   29%   14%  48%  58%  50%  45%  38% 179%  
 100%   43%   28%   13%  46%  56%  50%  40%  39% 174%  
 100%   60%   37%   20%  54%  62%  56%  51%  48% 179% 

• Many log messages with the keyword ssl_type:1 in mgwd.log

Wed Aug 12 02:14:59 2020:src/disp_processor.cc:1449 (thr_id:0x83cd63500) setup_transport() returned sock:192 stat:0 ssl_type:1
Wed Aug 12 02:14:59 2020:src/disp_processor.cc:1449 (thr_id:0x825b01100) setup_transport() returned sock:354 stat:0 ssl_type:1
Wed Aug 12 02:14:59 2020:src/disp_processor.cc:1449 (thr_id:0x83cd63500) setup_transport() returned sock:252 stat:0 ssl_type:1
Wed Aug 12 02:14:59 2020:src/disp_processor.cc:1449 (thr_id:0x825b01100) setup_transport() returned sock:246 stat:0 ssl_type:1
Wed Aug 12 02:14:59 2020:src/disp_processor.cc:1449 (thr_id:0x82e327200) setup_transport() returned sock:297 stat:0 ssl_type:1
Wed Aug 12 02:14:59 2020:src/disp_processor.cc:1449 (thr_id:0x83989b300) setup_transport() returned sock:197 stat:0 ssl_type:1