Fix: relayd: missing metadata stream causes all traces to be skipped

[lttng-tools.git] / src / bin / lttng-relayd / live.c

diff --git a/src/bin/lttng-relayd/live.c b/src/bin/lttng-relayd/live.c
index 3ca1797ed9b07b12468840f0bcd963709f72a92b..f00f07db1b8e63fc280c5a868379da2a47a68ade 100644 (file)
--- a/src/bin/lttng-relayd/live.c
+++ b/src/bin/lttng-relayd/live.c
@@ -309,6 +309,7 @@ static int make_viewer_streams(struct relay_session *session,
        rcu_read_lock();
        cds_lfht_for_each_entry(session->ctf_traces_ht->ht, &iter.iter, ctf_trace,
                        node.node) {
+               bool trace_has_metadata_stream = false;
                struct relay_stream *stream;
 
                health_code_update();
@@ -317,6 +318,30 @@ static int make_viewer_streams(struct relay_session *session,
                        continue;
                }
 
+               /*
+                * Iterate over all the streams of the trace to see if we have a
+                * metadata stream.
+                */
+               cds_list_for_each_entry_rcu(
+                               stream, &ctf_trace->stream_list, stream_node)
+               {
+                       if (stream->is_metadata) {
+                               trace_has_metadata_stream = true;
+                               break;
+                       }
+               }
+
+               /*
+                * If there is no metadata stream in this trace at the moment
+                * and we never sent one to the viewer, skip the trace. We
+                * accept that the viewer will not see this trace at all.
+                */
+               if (!trace_has_metadata_stream &&
+                               !ctf_trace->metadata_stream_sent_to_viewer) {
+                       ctf_trace_put(ctf_trace);
+                       continue;
+               }
+
                cds_list_for_each_entry_rcu(stream, &ctf_trace->stream_list, stream_node) {
                        struct relay_viewer_stream *vstream;
 
@@ -331,6 +356,15 @@ static int make_viewer_streams(struct relay_session *session,
                        }
                        vstream = viewer_stream_get_by_id(stream->stream_handle);
                        if (!vstream) {
+                               /*
+                                * Save that we sent the metadata stream to the
+                                * viewer. So that we know what trace the viewer
+                                * is aware of.
+                                */
+                               if (stream->is_metadata) {
+                                       ctf_trace->metadata_stream_sent_to_viewer =
+                                                       true;
+                               }
                                vstream = viewer_stream_create(stream,
                                                viewer_trace_chunk, seek_t);
                                if (!vstream) {