MINOR: stream/debug: make a stream dump and crash function

During 1.9 development (and even a bit after) we've started to face a
significant number of situations where streams were abusively spinning
due to an uncaught error flag or complex conditions that couldn't be
correctly identified. Sometimes streams wake appctx up and conversely
as well. More importantly when this happens the only fix is to restart.

This patch adds a new function to report a serious error, some relevant
info and to crash the process using abort() so that a core dump is
available. The purpose will be for this function to be called in various
situations where the process is unfixable. It will help detect these
issues much earlier during development and may even help fixing test
platforms which are able to automatically restart when such a condition
happens, though this is not the primary purpose.

This patch only provides the function and doesn't use it yet.

diff --git a/include/proto/stream.h b/include/proto/stream.h
index d99079ff90ca56cdbb0433716bbfcadf290e2df3..403ace1cb91a77cfc614b9f03b4aa563e13be1f4 100644 (file)
--- a/include/proto/stream.h
+++ b/include/proto/stream.h
@@ -41,6 +41,7 @@ int stream_create_from_cs(struct conn_stream *cs);
 
 /* kill a stream and set the termination flags to <why> (one of SF_ERR_*) */
 void stream_shutdown(struct stream *stream, int why);
+void stream_dump_and_crash(enum obj_type *obj, int rate);
 
 void stream_process_counters(struct stream *s);
 void sess_change_server(struct stream *sess, struct server *newsrv);

diff --git a/src/stream.c b/src/stream.c
index 1af563d6791daf4f928d4c5ac13c0294d6114548..4df5ff285f6a973819bec9b283025ff6bcabba82 100644 (file)
--- a/src/stream.c
+++ b/src/stream.c
@@ -2789,6 +2789,89 @@ void stream_shutdown(struct stream *stream, int why)
        task_wakeup(stream->task, TASK_WOKEN_OTHER);
 }
 
+/* dumps an error message for type <type> at ptr <ptr> related to stream <s>,
+ * having reached loop rate <rate>, then aborts hoping to retrieve a core. If
+ * <rate> is negative instead it reports a duration in microseconds.
+ */
+void stream_dump_and_crash(enum obj_type *obj, int rate)
+{
+       const struct conn_stream *csf, *csb;
+       const struct connection  *cof, *cob;
+       const struct appctx      *acf, *acb;
+       const struct server      *srv;
+       const struct stream *s;
+       const char *src = "unknown";
+       const char *dst = "unknown";
+       char pn[INET6_ADDRSTRLEN];
+       char *msg = NULL;
+       const char *fmt;
+       const struct channel *req, *res;
+       const struct stream_interface *si_f, *si_b;
+       const void *ptr;
+
+       ptr = s = objt_stream(obj);
+       if (!s) {
+               const struct appctx *appctx = objt_appctx(obj);
+               if (!appctx)
+                       return;
+               ptr = appctx;
+               s = si_strm(appctx->owner);
+               if (!s)
+                       return;
+       }
+
+       si_f = &s->si[0];
+       si_b = &s->si[1];
+       req = &s->req;
+       res = &s->res;
+
+       csf = objt_cs(si_f->end);
+       cof = cs_conn(csf);
+       acf = objt_appctx(si_f->end);
+       if (cof && addr_to_str(&cof->addr.from, pn, sizeof(pn)) >= 0)
+               src = pn;
+       else if (acf)
+               src = acf->applet->name;
+
+       csb = objt_cs(si_b->end);
+       cob = cs_conn(csb);
+       acb = objt_appctx(si_b->end);
+       srv = objt_server(s->target);
+       if (srv)
+               dst = srv->id;
+       else if (acb)
+               dst = acb->applet->name;
+
+       if (rate < 0) {
+               fmt = "A bogus %s [%p] halted the whole thread for at least %d microseconds "
+                     "resulting in a complete freeze of all other tasks, aborting now! Please "
+                     "report this error to developers "
+                     "[src=%s fe=%s be=%s dst=%s rqf=%x rqa=%x rpf=%x rpa=%x sif=%s,%x sib=%s,%x "
+                     "cof=%p,%x:%s/%s/%s/%d cob=%p,%x:%s/%s/%s/%d csf=%p,%x csb=%p,%x af=%p,%u ab=%p,%u]\n";
+               rate = -rate;
+       }
+       else {
+               fmt = "A bogus %s [%p] is spinning at %d calls per second and refuses to die, "
+                     "aborting now! Please report this error to developers "
+                     "[src=%s fe=%s be=%s dst=%s rqf=%x rqa=%x rpf=%x rpa=%x sif=%s,%x sib=%s,%x "
+                     "cof=%p,%x:%s/%s/%s/%d cob=%p,%x:%s/%s/%s/%d csf=%p,%x csb=%p,%x af=%p,%u ab=%p,%u]\n";
+       }
+
+       memprintf(&msg, fmt,
+                 obj_type_name(obj), ptr, rate, src, s->sess->fe->id, s->be->id, dst,
+                 req->flags, req->analysers, res->flags, res->analysers,
+                 si_state_str(si_f->state), si_f->flags,
+                 si_state_str(si_b->state), si_b->flags,
+                 cof, cof ? cof->flags : 0, conn_get_mux_name(cof), conn_get_xprt_name(cof), conn_get_ctrl_name(cof), cof?cof->handle.fd:0,
+                 cob, cob ? cob->flags : 0, conn_get_mux_name(cob), conn_get_xprt_name(cob), conn_get_ctrl_name(cob), cob?cob->handle.fd:0,
+                 csf, csf ? csf->flags : 0, csb, csb ? csb->flags : 0,
+                 acf, acf ? acf->st0   : 0, acb, acb ? acb->st0   : 0);
+
+       ha_alert("%s", msg);
+       send_log(NULL, LOG_EMERG, "%s", msg);
+       abort();
+}
+
 /************************************************************************/
 /*           All supported ACL keywords must be declared here.          */
 /************************************************************************/