Performance impact of DHCP Lease Scavenging [ Edited ]

[#1]

Does anybody have experience with the innitial performance impact of enabling DHCP Lease Scavenging? 

Infoblox documentation states: "Note: If you plan to enable this feature after upgrading from a previous NIOS version, Infoblox recommends that you enable it during off-peak hours, as it may impact DHCP services."
Configuring DHCP IPv4 and IPv6 Common Properties (infoblox.com)

I have 2 IB-1425 and an IB-V2215 as Grid Master with around 320.000 DHCP leases in the database of which are 220.000 in Free/Backup state. 
After enabling DHCP Lease Scavenging a big portion of these Free/Backup will get deleted.

How long will it take to clear the leases in database?

Will I notice a performance impact during lease cleanup? IB-1425 CPU is about 80% idle during peak hours, IB-V2215 is about 90% idle during peak hours. 

[#2]

Hello,

There is no actual way to know however there is a widget that you can check on how long it took after it ran.

here is a good guide for information:

https://www.infoblox.com/wp-content/uploads/2016/02/infoblox-deployment-guide-enabling-and-configuri...

Hope this helps,

Kevin Zettel

[#3]

Hi kzettel,

the widget and the documents seems to be only about DNS Scavenging.

In the meantime I got feedback from our Infoblox Support Engineer that the performance impact of the initial scavenging is not that big. 

Nevertheless I will enable it during low load hours in the next 2 weeks or so.

I will monitor the performance impact after enabling and give feedback here. 

[#4 · Accepted solution]

CPU load incresed from 10% to about 30% for about 3 minutes. Just a bit more than just restarting the DHCP service.