[Kea-users] Dropping the packets in load balancing

[Peter Davies]

Hi Kraishak, 
Looking at your log file, it appears that "Server A" only saw one unacked 
client, so it didn't transform to a partner-down state. I see several 
HA_COMMUNICATION_INTERRUPTED_CLIENT4 messages 
but only one 
HA_COMMUNICATION_INTERRUPTED_CLIENT4_UNACKED message. 

2023-05-15 16:07:30.127 INFO [kea-dhcp4.ha-hooks/32411.139751579436800] HA_COMMUNICATION_INTERRUPTED_CLIENT4_UNACKED [hwtype=1 34:98:b5:dc:1f:99], cid=[no info], tid=0x4be21c7f: partner server failed to respond, 1 clients unacked so far, 13 clients left before transitioning to the partner-down state 

Your configuration contains the following statement: 
"max-unacked-clients": 13 
The "max-ack-delay" parameter has a default value of 10000 ms. 
I suggest you check that your traffic generator correctly increments the "secs" 
field and to modify your HA settings appropriately. 

>From the Kea ARM: 

HA_COMMUNICATION_INTERRUPTED_CLIENT4 
%1: new client attempting to get a lease from the partner 
This informational message is issued when the surviving server observes a DHCP 
packet sent to the partner with which the communication is interrupted. The 
the client whose packet is observed is not yet considered “unacked” because the 
secs field value does not exceed the configured threshold specified with 
max-ack-delay. 

HA_COMMUNICATION_INTERRUPTED_CLIENT4_UNACKED 
%1: partner server failed to respond, %2 clients unacked so far, %3 clients left before transitioning to the partner-down state 
This informational message is issued when the surviving server determines that 
its partner failed to respond to the DHCP query and that this client is considered 
to not be served by the partner. The surviving server counts such clients, and if 
the number of such clients exceeds the max-unacked-clients threshold, the server 
will transition to the partner-down state. The first argument contains client 
identification information. The second argument specifies the number of clients 
to which the server has failed to respond. The third argument specifies the number 
of additional clients, which, if not provisioned, will cause the server to transition 
to the partner-down state. 

Kind Regards Peter 
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