From: Ben Pfaff Date: Thu, 13 Mar 2008 00:12:58 +0000 (-0700) Subject: Fix backoff. X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9df2b7bb71e50e05f63789658c91a73c175b6787;p=openvswitch Fix backoff. Until now, if the secure channel connected to a controller, then it would not back off at all from re-connecting. Therefore, if something causes the secure channel to disconnect quickly after connecting to a controller, then we could get storms of attempted connections. This commit causes the secure channel to back off exponentially from connection attempts regardless of the reason for disconnection, preventing such storms. --- diff --git a/secchan/secchan.c b/secchan/secchan.c index b8a4c4c3..e9df46d2 100644 --- a/secchan/secchan.c +++ b/secchan/secchan.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include "buffer.h" @@ -48,6 +49,8 @@ struct half { struct vconn *vconn; struct pollfd *pollfd; struct buffer *rxbuf; + time_t backoff_deadline; + int backoff; }; static void reconnect(struct half *); @@ -80,6 +83,8 @@ main(int argc, char *argv[]) halves[i].vconn = NULL; halves[i].pollfd = &pollfds[i]; halves[i].rxbuf = NULL; + halves[i].backoff_deadline = 0; + halves[i].backoff = 1; reconnect(&halves[i]); } for (;;) { @@ -156,8 +161,6 @@ main(int argc, char *argv[]) static void reconnect(struct half *this) { - int backoff; - if (this->vconn != NULL) { if (!reliable) { fatal(0, "%s: connection dropped", this->name); @@ -171,23 +174,38 @@ reconnect(struct half *this) } this->pollfd->revents = POLLIN | POLLOUT; - for (backoff = 1; ; backoff = MIN(backoff * 2, 60)) { - int retval = vconn_open(this->name, &this->vconn); + for (;;) { + time_t now = time(0); + int retval; + + if (now >= this->backoff_deadline) { + this->backoff = 1; + } else { + this->backoff *= 2; + if (this->backoff > 60) { + this->backoff = 60; + } + VLOG_WARN("%s: waiting %d seconds before reconnect\n", + this->name, (int) (this->backoff_deadline - now)); + sleep(this->backoff_deadline - now); + } + + retval = vconn_open(this->name, &this->vconn); if (!retval) { VLOG_WARN("%s: connected", this->name); if (vconn_is_passive(this->vconn)) { fatal(0, "%s: passive vconn not supported in control path", this->name); } + this->backoff_deadline = now + this->backoff; return; } if (!reliable) { fatal(0, "%s: connection failed", this->name); } - VLOG_WARN("%s: connection failed (%s), reconnecting", - this->name, strerror(errno)); - sleep(backoff); + VLOG_WARN("%s: connection failed (%s)", this->name, strerror(errno)); + this->backoff_deadline = time(0) + this->backoff; } }