diff options
| author | Quang-Minh Nguyen <qmnguyen@gitlab.com> | 2023-01-31 06:38:18 +0300 |
|---|---|---|
| committer | Quang-Minh Nguyen <qmnguyen@gitlab.com> | 2023-02-03 16:57:14 +0300 |
| commit | 908ba359cd7d3812447ee13b06b77254039fbb9e (patch) | |
| tree | e78c436ac6032992181a63f8a2220486aa8b9a4b /go.sum | |
| parent | a07b0212e689e3489aec99dcae6667e1315d27f4 (diff) | |
Implement a custom DNS Resolver for Gitaly
gRPC supports a built-in DNS resolver. This resolver works quite well
in most scenarios. It has some drawbacks:
- After the DNS is resolved for the first time, the resolver does not
refresh the list of addresses until the client connection triggers the
resolver actively. Client connection does so when it detects some of its
subchannels are unavailable permanently. It means as soon as the client
connection is stable, the client is not aware of new hosts added to
the cluster via DNS service discovery. This behavior leads to unexpected
stickiness and workload skew, especially after a failover.
- The support for SRV record is in a weird state. This type of record
is only supported when grpclb load balancing strategy is enabled. This
strategy is deprecated, unfortunately. Its behavior is also not as we
expected. In short-term, we would like to use round-robin strategy. In
longer term, we may have a custom strategy for Raft-based cluster. Thus,
SRV service discovery is crucial in the future.
- The resolver detects service config via TXT record if any. While this
option is convenient for a generic grpc setting, it does not make sense
for Gitaly. So, we should get rid of it.
This commit implements a custom DNS resolver. This resolver has some
major features:
- Resolve DNS service discovery via A records
- Periodically refresh the DNS (5 minutes by default)
- Update DNS state only if it detects real changes
- Support logging
Service discovery via SRV records is not supported in this version to
keep the backward compatibility with Ruby clients.
Diffstat (limited to 'go.sum')
| -rw-r--r-- | go.sum | 2 |
1 files changed, 2 insertions, 0 deletions
@@ -1569,6 +1569,7 @@ github.com/miekg/dns v1.0.14/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3N github.com/miekg/dns v1.1.26/go.mod h1:bPDLeHnStXmXAq1m/Ch/hvfNHr14JKNPMBo3VZKjuso= github.com/miekg/dns v1.1.41/go.mod h1:p6aan82bvRIyn+zDIv9xYNUpwa73JcSh9BKwknJysuI= github.com/miekg/dns v1.1.48/go.mod h1:e3IlAVfNqAllflbibAZEWOXOQ+Ynzk/dDozDxY7XnME= +github.com/miekg/dns v1.1.50 h1:DQUfb9uc6smULcREF09Uc+/Gd46YWqJd5DbpPE9xkcA= github.com/miekg/dns v1.1.50/go.mod h1:e3IlAVfNqAllflbibAZEWOXOQ+Ynzk/dDozDxY7XnME= github.com/miekg/pkcs11 v1.0.3/go.mod h1:XsNlhZGX73bx86s2hdc/FuaLm2CPZJemRLMA+WTFxgs= github.com/mistifyio/go-zfs v2.1.2-0.20190413222219-f784269be439+incompatible/go.mod h1:8AuVvqP/mXw1px98n46wfvcGfQ4ci2FwoAjKYxuo3Z4= @@ -2212,6 +2213,7 @@ golang.org/x/mod v0.5.0/go.mod h1:5OXOZSfqPIIbmVBIIKWRFfZjPR0E5r58TLhUjH0a2Ro= golang.org/x/mod v0.5.1/go.mod h1:5OXOZSfqPIIbmVBIIKWRFfZjPR0E5r58TLhUjH0a2Ro= golang.org/x/mod v0.6.0-dev.0.20220106191415-9b9b3d81d5e3/go.mod h1:3p9vT2HGsQu2K1YbXdKPJLVgG5VJdoTa1poYQBtP1AY= golang.org/x/mod v0.6.0-dev.0.20220419223038-86c51ed26bb4/go.mod h1:jJ57K6gSWd91VN4djpZkiMVwK6gcyfeH4XE8wZrZaV4= +golang.org/x/mod v0.6.0 h1:b9gGHsz9/HhJ3HF5DHQytPpuwocVTChQJK3AvoLRD5I= golang.org/x/mod v0.6.0/go.mod h1:4mET923SAdbXp2ki8ey+zGs1SLqsuM2Y0uvdZR/fUNI= golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4= golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4= |