lib/handshake: add SetReadDeadline and SetWriteDeadline implementations additionally to SetDeadline

This is a follow-up for 27a5461785

Updates https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5327

docs/CHANGELOG.md

@@ -31,6 +31,7 @@ The sandbox cluster installation is running under the constant load generated by
 * FEATURE: dashboards: use `version` instead of `short_version` in version change annotation for single/cluster dashboards. The update should reflect version changes even if different flavours of the same release were applied (custom builds).
 
 * BUGFIX: fix a bug, which could result in improper results and/or to `cannot merge series: duplicate series found` error during [range query](https://docs.victoriametrics.com/keyConcepts.html#range-query) execution. The issue has been introduced in [v1.95.0](https://docs.victoriametrics.com/CHANGELOG.html#v1950). See [this bugreport](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5332) for details.
+* BUGFIX: improve deadline detection when using buffered connection for communication between cluster components. Before, due to nature of a buffered connection the deadline could have been exceeded while reading or writing buffered data to connection. See [this pull request](https://github.com/VictoriaMetrics/VictoriaMetrics/pull/5327).
 
 ## [v1.95.0](https://github.com/VictoriaMetrics/VictoriaMetrics/releases/tag/v1.95.0)
 
@@ -101,7 +102,6 @@ Released at 2023-11-15
 * BUGFIX: [vmalert](https://docs.victoriametrics.com/vmalert.html): increment `vmalert_remotewrite_errors_total` metric if all retries to send remote-write request failed. Before, this metric was incremented only if remote-write client's buffer is overloaded.
 * BUGFIX: [vmalert](https://docs.victoriametrics.com/vmalert.html): increment `vmalert_remotewrite_dropped_rows_total` and `vmalert_remotewrite_dropped_bytes_total` metrics if remote-write client's buffer is overloaded. Before, these metrics were incremented only after unsuccessful HTTP calls.
 * BUGFIX: `vmselect`: improve performance and memory usage during query processing on machines with big number of CPU cores. See [this issue](https://github.com/VictoriaMetrics/VictoriaMetrics/issues/5087).
-* BUGFIX: improve deadline detection when using buffered connection for communication between cluster components. Before, due to nature of a buffered connection the deadline could have been exceeded while reading or writing data to connection.
 * BUGFIX: dashboards: fix vminsert/vmstorage/vmselect metrics filtering when dashboard is used to display data from many sub-clusters with unique job names. Before, only one specific job could have been accounted for component-specific panels, instead of all available jobs for the component.
 * BUGFIX: dashboards: respect `job` and `instance` filters for `alerts` annotation in cluster and single-node dashboards.
 * BUGFIX: dashboards: update description for RSS and anonymous memory panels to be consistent for single-node, cluster and vmagent dashboards.

lib/handshake/buffered_conn.go

@@ -23,7 +23,8 @@ type BufferedConn struct {
 	br io.Reader
 	bw bufferedWriter
 
-	deadline time.Time
+	readDeadline  time.Time
+	writeDeadline time.Time
 }
 
 const bufferSize = 64 * 1024
@@ -46,17 +47,35 @@ func newBufferedConn(c net.Conn, compressionLevel int, isReadCompressed bool) *B
 	return bc
 }
 
-// SetDeadline sets the read and write deadlines associated with the connection.
-// Deadline is checked on each Read call.
+// SetDeadline sets read and write deadlines for bc to t.
+//
+// Deadline is checked on each Read and Write call.
 func (bc *BufferedConn) SetDeadline(t time.Time) error {
-	bc.deadline = t
+	bc.readDeadline = t
+	bc.writeDeadline = t
 	return bc.Conn.SetDeadline(t)
 }
 
+// SetReadDeadline sets read deadline for bc to t.
+//
+// Deadline is checked on each Read call.
+func (bc *BufferedConn) SetReadDeadline(t time.Time) error {
+	bc.readDeadline = t
+	return bc.Conn.SetReadDeadline(t)
+}
+
+// SetWriteDeadline sets write deadline for bc to t.
+//
+// Deadline is checked on each Write call.
+func (bc *BufferedConn) SetWriteDeadline(t time.Time) error {
+	bc.writeDeadline = t
+	return bc.Conn.SetReadDeadline(t)
+}
+
 // Read reads up to len(p) from bc to p.
 func (bc *BufferedConn) Read(p []byte) (int, error) {
 	startTime := time.Now()
-	if startTime.After(bc.deadline) {
+	if deadlineExceeded(bc.readDeadline, startTime) {
 		return 0, os.ErrDeadlineExceeded
 	}
 	n, err := bc.br.Read(p)
@@ -71,7 +90,7 @@ func (bc *BufferedConn) Read(p []byte) (int, error) {
 // Do not forget to call Flush if needed.
 func (bc *BufferedConn) Write(p []byte) (int, error) {
 	startTime := time.Now()
-	if startTime.After(bc.deadline) {
+	if deadlineExceeded(bc.writeDeadline, startTime) {
 		return 0, os.ErrDeadlineExceeded
 	}
 	n, err := bc.bw.Write(p)
@@ -81,6 +100,13 @@ func (bc *BufferedConn) Write(p []byte) (int, error) {
 	return n, err
 }
 
+func deadlineExceeded(deadline, currentTime time.Time) bool {
+	if deadline.IsZero() {
+		return false
+	}
+	return currentTime.After(deadline)
+}
+
 // Close closes bc.
 func (bc *BufferedConn) Close() error {
 	// Close the Conn at first. It is expected that all the required data