10.3. Memory Monitoring#
There are two types of memory:
System memory used by dynamic routing protocols, SSH, SNMP, etc.
Hugepages for Data Plane. Most memory from hugepages is allocated statically (Sessions, Mappings, Subscribers, Hash Tables), but there is also memory, which is allocated during usage (when creating pools, VRFs, or ACLs, for example).
To monitor memory correctly, we recommend using the following OIDs:
Total System Memory = All Memory - All Hugepages
.1.3.6.1.4.1.2021.4.5.0 - Total System Memory
.1.3.6.1.4.1.46576.1.2.0.2.1.2.0 - HugePages Total (NUMA node0)
.1.3.6.1.4.1.46576.1.2.0.2.1.2.1 - HugePages Total (NUMA node1)
.1.3.6.1.4.1.2021.4.5.0 - (.1.3.6.1.4.1.46576.1.2.0.2.1.2.0 + .1.3.6.1.4.1.46576.1.2.0.2.1.2.1)
Free system memory: Free + Buffered + Cached:
.1.3.6.1.4.1.2021.4.11.0 + .1.3.6.1.4.1.2021.4.14.0 + .1.3.6.1.4.1.2021.4.15.0
Memory in vCGNAT is divided by NUMA nodes. It is better to monitor it separately:
Total Hugepages NUMA node0: .1.3.6.1.4.1.46576.1.2.0.2.1.2.0
Total Hugepages NUMA node1: .1.3.6.1.4.1.46576.1.2.0.2.1.2.1
Used memory:
NUMA node0: .1.3.6.1.4.1.46576.1.2.0.2.1.4.0
NUMA node1: .1.3.6.1.4.1.46576.1.2.0.2.1.4.1
Free memory:
NUMA node0: .1.3.6.1.4.1.46576.1.2.0.2.1.3.0
NUMA node1: .1.3.6.1.4.1.46576.1.2.0.2.1.3.1
Alternatively, you can use a command via CLI to determine how much memory is used:
- show memory dataplane#
Display Dataplane memory information for all sockets. The output shows the vCGNAT objects and their size in Bytes. Their total size is given at the bottom of the output. The summary statistic gives the total amount of memory allocated by vCGNAT, the memory used, the free memory, and the load percentage.
Another useful command is:
- show memory dataplane pools#
Display memory statistics for memory pools for all sockets. When vCGNAT is started, memory pools are allocated statically. The output shows the total, used, and free number of subscribers, mappings, sessions, etc. This command can be used to monitor memory pool utilization. If vCGNAT cannot, for example, allocate sessions from the memory pool, drops will appear in the corresponding column. The critical load value is 90%. The total number of subscribers, mappings, sessions, etc., can be changed in the platform settings. The output is as follows:
vcgnat# show memory dataplane pools --------------------------------------------------------------------------------------- Statistics for Socket 0 --------------------------------------------------------------------------------------- Total Used Free Drops Load --------------------------------------------------------------------------------------- Subscribers 1527648 161520 1366128 0 10.6% Mappings 85027648 1096285 83931363 0 1.3% Sessions 85027648 1164505 83863143 0 1.4% Fragments 65536 0 65536 0 0.0% Pending Fragments 1024 2 1022 0 0.2% --------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------- Statistics for Socket 1 --------------------------------------------------------------------------------------- Total Used Free Drops Load --------------------------------------------------------------------------------------- Subscribers 1527648 144786 1382862 0 9.5% Mappings 85027648 970063 84057585 0 1.1% Sessions 85027648 1030252 83997396 0 1.2% Fragments 65536 4 65532 0 0.0% Pending Fragments 1024 2 1022 0 0.2% --------------------------------------------------------------------------------------- --------------------------------------------------------------------------------------- Total Used Free Drops Load --------------------------------------------------------------------------------------- IPv4 neighbors 1024 12 1012 0 1.2% IPv6 neighbors 1024 0 1024 0 0.0% ARP wait_ctx 0 69632 15 69617 0 0.0% ARP wait_ctx 1 69632 15 69617 0 0.0% ---------------------------------------------------------------------------------------