Report more information about queried servers.
This change causes the Go client to report the timespan and query
duration for each server queried.
Change-Id: I5ddb8e3fe7a7877dbc184f64f82d9d1f5236344e
diff --git a/go/client/client.go b/go/client/client.go
index 004f829..6ecf332 100644
--- a/go/client/client.go
+++ b/go/client/client.go
@@ -190,6 +190,10 @@
// max is the maximum real-time (in Roughtime UTC microseconds) that
// could correspond to |base| (i.e. midpoint + radius + query time).
max *big.Int
+
+ // queryDuration contains the amount of time that the server took to
+ // answer the query.
+ queryDuration time.Duration
}
// midpoint returns the average of the min and max times.
@@ -298,7 +302,7 @@
Reply: reply,
})
- queryDurationBig := new(big.Int).SetInt64(int64(queryDuration/time.Microsecond))
+ queryDurationBig := new(big.Int).SetInt64(int64(queryDuration / time.Microsecond))
bigRadius := new(big.Int).SetUint64(uint64(radius))
min := new(big.Int).SetUint64(midpoint)
min.Sub(min, bigRadius)
@@ -308,10 +312,11 @@
max.Add(max, bigRadius)
return &timeSample{
- server: server,
- base: new(big.Int).SetInt64(int64(baseTime)),
- min: min,
- max: max,
+ server: server,
+ base: new(big.Int).SetInt64(int64(baseTime)),
+ min: min,
+ max: max,
+ queryDuration: queryDuration,
}, nil
}
@@ -463,12 +468,26 @@
// ServerErrors maps from server name to query error.
ServerErrors map[string]error
+ // ServerInfo contains information about each server that was queried.
+ ServerInfo map[string]ServerInfo
+
// OutOfRangeAnswer is true if one or more of the queries contained a
// significantly incorrect time, as defined by MaxDifference. In this
// case, the reply will have been recorded in the chain.
OutOfRangeAnswer bool
}
+// ServerInfo contains information from a specific server.
+type ServerInfo struct {
+ // QueryDuration is the amount of time that the server took to answer.
+ QueryDuration time.Duration
+
+ // Min and Max specify the time window given by the server. These
+ // values have been adjusted so that they are comparible across
+ // servers, even though they are queried at different times.
+ Min, Max *big.Int
+}
+
// EstablishTime queries a number of servers until it has a quorum of
// overlapping results, or it runs out of servers. Results from the querying
// the servers are appended to chain.
@@ -496,6 +515,15 @@
}
samples = append(samples, sample)
+ if result.ServerInfo == nil {
+ result.ServerInfo = make(map[string]ServerInfo)
+ }
+ result.ServerInfo[server.Name] = ServerInfo{
+ QueryDuration: sample.queryDuration,
+ Min: sample.min,
+ Max: sample.max,
+ }
+
var ok bool
if intersection, ok = findNOverlapping(samples, quorum); ok {
break
diff --git a/go/client/main.go b/go/client/main.go
index b74e95b..a410f97 100644
--- a/go/client/main.go
+++ b/go/client/main.go
@@ -21,6 +21,7 @@
"io/ioutil"
"os"
"path/filepath"
+ "strings"
"time"
"roughtime.googlesource.com/go/client/monotime"
@@ -81,6 +82,17 @@
fmt.Fprintf(os.Stderr, "Failed to query %q: %s\n", serverName, err)
}
+ maxLenServerName := 0
+ for name := range result.ServerInfo {
+ if len(name) > maxLenServerName {
+ maxLenServerName = len(name)
+ }
+ }
+
+ for name, info := range result.ServerInfo {
+ fmt.Printf("%s:%s %d–%d (answered in %s)\n", name, strings.Repeat(" ", maxLenServerName-len(name)), info.Min, info.Max, info.QueryDuration)
+ }
+
if result.MonoUTCDelta == nil {
fmt.Fprintf(os.Stderr, "Failed to get %d servers to agree on the time.\n", quorum)
} else {
