Use round robin for happy eyeballs DNS responses (load balancing)#247
Merged
jsor merged 1 commit intoreactphp:masterfrom Sep 6, 2020
Merged
Use round robin for happy eyeballs DNS responses (load balancing)#247jsor merged 1 commit intoreactphp:masterfrom
jsor merged 1 commit intoreactphp:masterfrom
Conversation
The happy eyeballs algorithms tries to connect over both IPv6 and IPv4 at the same time. Accordingly, the hostname has to be resolved for both address families which both may potentially contain any number of records (load balancing). This changeset randomizes the order of returned IP addresses per address family. This means that if multiple records are returned, it will try to connect to a random one from this list instead of always trying the first. This allows the load to be distributed more evenly across all returned IP addresses. This can be used as a very basic DNS load balancing mechanism.
WyriHaximus
approved these changes
Sep 5, 2020
jsor
approved these changes
Sep 6, 2020
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
The happy eyeballs algorithms tries to connect over both IPv6 and IPv4
at the same time. Accordingly, the hostname has to be resolved for both
address families which both may potentially contain any number of
records (load balancing).
This changeset randomizes the order of returned IP addresses per address
family. This means that if multiple records are returned, it will try to
connect to a random one from this list instead of always trying the
first. This allows the load to be distributed more evenly across all
returned IP addresses. This can be used as a very basic DNS load
balancing mechanism.
This is similar to what the old
DnsConnectordid (it always tried one random IP from the list of IPs). See also https://daniel.haxx.se/blog/2012/01/03/getaddrinfo-with-round-robin-dns-and-happy-eyeballs/ for some background information.