Split the is_importing stat in two

We want to use two new different sockstats,
`import_skip_push_limit` and `import_soft_throttling`
which are respectively used to allow a higher push limit,
and implement soft throttling policy for imports.

We still forward the `is_importing` stat for to skip
push limit for backward compatibility. We plan to
remove it on a subsequent PR.

Author: elhmn

internal/governor/conn.go

@@ -211,6 +211,10 @@ func readSockstat(environ []string) updateData {
 			res.GroupLeader = sockstat.GetBool(parts[1])
 		case "is_importing":
 			res.IsImporting = sockstat.BoolValue(parts[1])
+		case "import_skip_push_limit":
+			res.ImportSkipPushLimit = sockstat.BoolValue(parts[1])
+		case "import_soft_throttling":
+			res.ImportSoftThrottling = sockstat.BoolValue(parts[1])
 		}
 	}
 

internal/governor/governor.go

@@ -76,6 +76,12 @@ type updateData struct {
 	CommandID string `json:"command_id,omitempty"`
 	// IsImporting is true if the command is an import.
 	IsImporting bool `json:"is_importing,omitempty"`
+	// ImportSkipPushLimit is true if the command is an import and
+	// we want to skip the push limit for a command.
+	ImportSkipPushLimit bool `json:"import_skip_push_limit,omitempty"`
+	// ImportSoftThrottling is true if the command is an import and
+	// we want to apply it some soft throttling policies.
+	ImportSoftThrottling bool `json:"import_soft_throttling,omitempty"`
 }
 
 func update(w io.Writer, ud updateData) error {

internal/spokes/spokes.go

@@ -955,7 +955,11 @@ func (r *spokesReceivePack) isFsckConfigEnabled() bool {
 }
 
 func (r *spokesReceivePack) getMaxInputSize() (int, error) {
-	if isImporting() {
+	// We want to skip the default push limit when the `import_skip_push_limit`
+	// stat is set only.
+	// We keep using the `is_import` here for backward compatibility only,
+	// which should be removed on a subsequent PR.
+	if isImporting() || skipPushLimit() {
 		return 80 * 1024 * 1024 * 1024, nil /* 80 GB */
 	}
 
@@ -1234,6 +1238,10 @@ func isImporting() bool {
 	return sockstat.GetBool("is_importing")
 }
 
+func skipPushLimit() bool {
+	return sockstat.GetBool("import_skip_push_limit")
+}
+
 func allowBadDate() bool {
 	return isImporting() && sockstat.GetBool("allow_baddate_in_import")
 }