status-im
/
consul
mirror of https://github.com/status-im/consul.git
2
0
Fork 0
Code Issues Projects Releases Wiki Activity

Use the maximum jitter when calculating the timeout 

The timeout should include the maximum possible
jitter since the server will randomly add to it's
timeout a jitter. If the server's timeout is less
than the client's timeout then the client will
return an i/o deadline reached error.

Before:
```
time curl 'http://localhost:8500/v1/catalog/service/service?dc=other-dc&stale=&wait=600s&index=15820644'
rpc error making call: i/o deadline reached
real    10m11.469s
user    0m0.018s
sys     0m0.023s
```

After:
```
time curl 'http://localhost:8500/v1/catalog/service/service?dc=other-dc&stale=&wait=600s&index=15820644'
[...]
real    10m35.835s
user    0m0.021s
sys     0m0.021s
```
This commit is contained in:
James Hartig 2022-08-16 16:54:01 -04:00 committed by Chris S. Kim
parent 1c728ebcbb
commit f92883bbce
3 changed files with 8 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
.changelog/14233.txt Normal file
View File

@ -0,0 +1,3 @@
```release-note:bugfix
rpc: Adds max jitter to client deadlines to prevent i/o deadline errors on blocking queries
```

7
agent/consul/client_test.go
View File

@ -893,8 +893,8 @@ func TestClient_RPC_Timeout(t *testing.T) {
}
})
// waiter will sleep for 50ms
require.NoError(t, s1.RegisterEndpoint("Wait", &waiter{duration: 50 * time.Millisecond}))
// waiter will sleep for 101ms which is 1ms more than the DefaultQueryTime
require.NoError(t, s1.RegisterEndpoint("Wait", &waiter{duration: 101 * time.Millisecond}))
// Requests with QueryOptions have a default timeout of RPCHoldTimeout (10ms)
// so we expect the RPC call to timeout.
@ -903,7 +903,8 @@ func TestClient_RPC_Timeout(t *testing.T) {
require.Error(t, err)
require.Contains(t, err.Error(), "rpc error making call: i/o deadline reached")
// Blocking requests have a longer timeout (100ms) so this should pass
// Blocking requests have a longer timeout (100ms) so this should pass since we
// add the maximum jitter which should be 16ms
out = struct{}{}
err = c1.RPC("Wait.Wait", &structs.NodeSpecificRequest{
QueryOptions: structs.QueryOptions{

2
agent/structs/structs.go
View File

@ -353,7 +353,7 @@ func (q QueryOptions) Timeout(rpcHoldTimeout, maxQueryTime, defaultQueryTime tim
q.MaxQueryTime = defaultQueryTime
}
// Timeout after maximum jitter has elapsed.
q.MaxQueryTime += lib.RandomStagger(q.MaxQueryTime / JitterFraction)
q.MaxQueryTime += q.MaxQueryTime / JitterFraction
return q.MaxQueryTime + rpcHoldTimeout
}