Documentation update

[l2tpns.git] / cluster.c

diff --git a/cluster.c b/cluster.c
index a251a77..91fc3b1 100644 (file)
--- a/cluster.c
+++ b/cluster.c
@@ -1,6 +1,6 @@
 // L2TPNS Clustering Stuff
 
 // L2TPNS Clustering Stuff
 

-char const *cvs_id_cluster = "$Id: cluster.c,v 1.7 2004-07-07 09:09:53 bodea Exp $";
+char const *cvs_id_cluster = "$Id: cluster.c,v 1.9 2004-07-11 07:57:35 bodea Exp $";

 
 #include <stdio.h>
 #include <sys/file.h>
 
 #include <stdio.h>
 #include <sys/file.h>


@@ -66,7 +66,6 @@ static struct {
        int     uptodate;
 } peers[CLUSTER_MAX_SIZE];     // List of all the peers we've heard from.
 static int num_peers;          // Number of peers in list.
        int     uptodate;
 } peers[CLUSTER_MAX_SIZE];     // List of all the peers we've heard from.
 static int num_peers;          // Number of peers in list.

-static int have_peers;         // At least one up to date peer

 
 int rle_decompress(u8 ** src_p, int ssize, u8 *dst, int dsize);
 int rle_compress(u8 ** src_p, int ssize, u8 *dst, int dsize);
 
 int rle_decompress(u8 ** src_p, int ssize, u8 *dst, int dsize);
 int rle_compress(u8 ** src_p, int ssize, u8 *dst, int dsize);


@@ -330,13 +329,6 @@ int master_garden_packet(sessionidt s, char *data, int size)
 static void send_heartbeat(int seq, char * data, int size)
 {
     int i;
 static void send_heartbeat(int seq, char * data, int size)
 {
     int i;

-    static int last_seq = -1;
-
-    if (last_seq != -1 && (seq != (last_seq+1)%HB_MAX_SEQ) ) {
-       log(0,0,0,0, "FATAL: Sequence number skipped! (%d != %d)\n",
-               seq, last_seq);
-    } 
-    last_seq = seq;

 
     if (size > sizeof(past_hearts[0].data)) {
        log(0,0,0,0, "Tried to heartbeat something larger than the maximum packet!\n");
 
     if (size > sizeof(past_hearts[0].data)) {
        log(0,0,0,0, "Tried to heartbeat something larger than the maximum packet!\n");


@@ -426,6 +418,48 @@ void master_update_counts(void)
        return;
 }
 
        return;
 }
 

+//
+// On the master, check how our slaves are going. If
+// one of them's not up-to-date we'll heartbeat faster.
+// If we don't have any of them, then we need to turn
+// on our own packet handling!
+//
+void cluster_check_slaves(void)
+{
+       int i;
+       static int have_peers = 0;
+       int had_peers = have_peers;
+       clockt t = TIME;
+
+       if (!config->cluster_iam_master)
+               return;         // Only runs on the master...
+
+       config->cluster_iam_uptodate = 1;       // cleared in loop below
+
+       for (i = have_peers = 0; i < num_peers; i++)
+       {
+               if ((peers[i].timestamp + config->cluster_hb_timeout) < t)
+                       continue;       // Stale peer! Skip them.
+
+               if (!peers[i].basetime)
+                       continue;       // Shutdown peer! Skip them.
+
+               if (peers[i].uptodate)
+                       have_peers = 1;
+
+               if (!peers[i].uptodate)
+                       config->cluster_iam_uptodate = 0; // Start fast heartbeats
+       }
+
+#ifdef BGP
+       // master lost all slaves, need to handle traffic ourself
+       if (bgp_configured && had_peers && !have_peers)
+               bgp_enable_routing(1);
+       else if (bgp_configured && !had_peers && have_peers)
+               bgp_enable_routing(0);
+#endif /* BGP */
+}
+

 //
 // Check that we have a master. If it's been too
 // long since we heard from a master then hold an election.
 //
 // Check that we have a master. If it's been too
 // long since we heard from a master then hold an election.


@@ -434,48 +468,40 @@ void cluster_check_master(void)
 {
        int i, count, tcount, high_sid = 0;
        int last_free = 0;
 {
        int i, count, tcount, high_sid = 0;
        int last_free = 0;

-       int had_peers = have_peers;

        clockt t = TIME;
        static int probed = 0;
 
        clockt t = TIME;
        static int probed = 0;
 

-       if (TIME < (config->cluster_last_hb + config->cluster_hb_timeout))
-       {
+       if (config->cluster_iam_master)
+               return;         // Only runs on the slaves...
+

                // If the master is late (missed 2 hearbeats by a second and a
                // hair) it may be that the switch has dropped us from the
                // multicast group, try unicasting one probe to the master
                // which will hopefully respond with a unicast heartbeat that
                // will allow us to limp along until the querier next runs.
                // If the master is late (missed 2 hearbeats by a second and a
                // hair) it may be that the switch has dropped us from the
                // multicast group, try unicasting one probe to the master
                // which will hopefully respond with a unicast heartbeat that
                // will allow us to limp along until the querier next runs.

-               if (config->cluster_master_address
-                   && TIME > (config->cluster_last_hb + 2 * config->cluster_hb_interval + 11))
+       if (TIME > (config->cluster_last_hb + 2 * config->cluster_hb_interval + 11))
+       {
+               if (!probed && config->cluster_master_address)

                {
                {

-                       if (!probed)
-                       {
-                               probed = 1;
-                               log(1, 0, 0, 0, "Heartbeat from master %.1fs late, probing...\n",
-                                   TIME - (config->cluster_last_hb + config->cluster_hb_interval));
-
-                               peer_send_message(config->cluster_master_address,
-                                   C_LASTSEEN, config->cluster_seq_number, NULL, 0);
-                       }
-               } else {        // We got a recent heartbeat; reset the probe flag.
-                       probed = 0;
-               }
+                       probed = 1;
+                       log(1, 0, 0, 0, "Heartbeat from master %.1fs late, probing...\n",
+                           0.1 * (TIME - (config->cluster_last_hb + config->cluster_hb_interval)));

 
 

-               if (!config->cluster_iam_master)
-                       return;         // Everything's ok. return.
-
-               // Master needs to check peer state
+                       peer_send_message(config->cluster_master_address,
+                           C_LASTSEEN, config->cluster_seq_number, NULL, 0);
+               }
+       } else {        // We got a recent heartbeat; reset the probe flag.
+               probed = 0;

        }
 
        }
 

-       config->cluster_last_hb = TIME + 1;
+       if (TIME < (config->cluster_last_hb + config->cluster_hb_timeout))
+               return; // Everything's ok!

 
 

-       if (config->cluster_iam_master)
-               config->cluster_iam_uptodate = 1;       // cleared in loop below
-       else
-               log(0,0,0,0, "Master timed out! Holding election...\n");
+       config->cluster_last_hb = TIME + 1;     // Just the one election thanks.

 
 

+       log(0,0,0,0, "Master timed out! Holding election...\n");

 
 

-       for (i = have_peers = 0; i < num_peers; i++)
+       for (i = 0; i < num_peers; i++)

        {
                if ((peers[i].timestamp + config->cluster_hb_timeout) < t)
                        continue;       // Stale peer! Skip them.
        {
                if ((peers[i].timestamp + config->cluster_hb_timeout) < t)
                        continue;       // Stale peer! Skip them.


@@ -483,17 +509,6 @@ void cluster_check_master(void)
                if (!peers[i].basetime)
                        continue;       // Shutdown peer! Skip them.
 
                if (!peers[i].basetime)
                        continue;       // Shutdown peer! Skip them.
 

-               if (peers[i].uptodate)
-                       have_peers = 1;
-
-               if (config->cluster_iam_master)
-               {
-                       if (!peers[i].uptodate)
-                               config->cluster_iam_uptodate = 0; // Start fast heartbeats
-
-                       continue;
-               }
-

                if (peers[i].basetime < basetime) {
                        log(1,0,0,0, "Expecting %s to become master\n", inet_toa(peers[i].peer) );
                        return;         // They'll win the election. Get out of here.
                if (peers[i].basetime < basetime) {
                        log(1,0,0,0, "Expecting %s to become master\n", inet_toa(peers[i].peer) );
                        return;         // They'll win the election. Get out of here.


@@ -506,16 +521,6 @@ void cluster_check_master(void)
                }
        }
 
                }
        }
 

-       if (config->cluster_iam_master)         // If we're the master, we've already won
-       {
-#ifdef BGP
-               // master lost all slaves, need to handle traffic ourself
-               if (bgp_configured && had_peers && !have_peers)
-                       bgp_enable_routing(1);
-#endif /* BGP */
-               return;
-       }
-

                // Wow. it's been ages since I last heard a heartbeat
                // and I'm better than an of my peers so it's time
                // to become a master!!!
                // Wow. it's been ages since I last heard a heartbeat
                // and I'm better than an of my peers so it's time
                // to become a master!!!


@@ -525,11 +530,6 @@ void cluster_check_master(void)
 
        log(0,0,0,0, "I am declaring myself the master!\n");
 
 
        log(0,0,0,0, "I am declaring myself the master!\n");
 

-#ifdef BGP
-       if (bgp_configured && have_peers)
-               bgp_enable_routing(0); /* stop handling traffic */
-#endif /* BGP */
-

        if (config->cluster_seq_number == -1)
                config->cluster_seq_number = 0;
 
        if (config->cluster_seq_number == -1)
                config->cluster_seq_number = 0;
 


@@ -897,13 +897,8 @@ int cluster_catchup_slave(int seq, u32 slave)
        while (seq != config->cluster_seq_number) {
                s = seq%HB_HISTORY_SIZE;
                if (seq != past_hearts[s].seq) {
        while (seq != config->cluster_seq_number) {
                s = seq%HB_HISTORY_SIZE;
                if (seq != past_hearts[s].seq) {

-                       int i;

                        log(0,0,0,0, "Tried to re-send heartbeat for %s but %d doesn't match %d! (%d,%d)\n",
                                inet_toa(slave), seq, past_hearts[s].seq, s, config->cluster_seq_number);
                        log(0,0,0,0, "Tried to re-send heartbeat for %s but %d doesn't match %d! (%d,%d)\n",
                                inet_toa(slave), seq, past_hearts[s].seq, s, config->cluster_seq_number);

-
-                       for (i = 0; i < HB_HISTORY_SIZE; ++i) {
-                               log(0,0,0,0, "\tentry %3d: seq %d (size %d)\n", i, past_hearts[s].seq, past_hearts[s].size);
-                       }

                        return -1;      // What to do here!?
                }
                peer_send_data(slave, past_hearts[s].data, past_hearts[s].size);
                        return -1;      // What to do here!?
                }
                peer_send_data(slave, past_hearts[s].data, past_hearts[s].size);


@@ -916,12 +911,25 @@ int cluster_catchup_slave(int seq, u32 slave)
 // We've heard from another peer! Add it to the list
 // that we select from at election time.
 //
 // We've heard from another peer! Add it to the list
 // that we select from at election time.
 //

-int cluster_add_peer(u32 peer, time_t basetime, pingt *p)
+int cluster_add_peer(u32 peer, time_t basetime, pingt *pp, int size)

 {
        int i;
        u32 clusterid;
 {
        int i;
        u32 clusterid;

+       pingt p;
+       
+
+               // Allow for backward compatability.
+               // Just the ping packet into a new structure to allow
+               // for the possibility that we might have received
+               // more or fewer elements than we were expecting.
+       if (size > sizeof(p))
+               size = sizeof(p);
+
+       memset( (void*) &p, 0, sizeof(p) );
+       memcpy( (void*) &p, (void*) pp, size);
+       

 
 

-       clusterid = p->addr;
+       clusterid = p.addr;

        if (clusterid != config->bind_address)
        {
                // Is this for us?
        if (clusterid != config->bind_address)
        {
                // Is this for us?


@@ -937,12 +945,13 @@ int cluster_add_peer(u32 peer, time_t basetime, pingt *p)
                // This peer already exists. Just update the timestamp.
                peers[i].basetime = basetime;
                peers[i].timestamp = TIME;
                // This peer already exists. Just update the timestamp.
                peers[i].basetime = basetime;
                peers[i].timestamp = TIME;

-               peers[i].uptodate = !p->undef;
+               peers[i].uptodate = !p.undef;

                break;
        }
 
                // Is this the master shutting down??
        if (peer == config->cluster_master_address && !basetime) {
                break;
        }
 
                // Is this the master shutting down??
        if (peer == config->cluster_master_address && !basetime) {

+               log(3,0,0,0, "Master %s shutting down...\n", inet_toa(config->cluster_master_address));

                config->cluster_master_address = 0;
                config->cluster_last_hb = 0; // Force an election.
                cluster_check_master();
                config->cluster_master_address = 0;
                config->cluster_last_hb = 0; // Force an election.
                cluster_check_master();


@@ -973,28 +982,13 @@ int cluster_add_peer(u32 peer, time_t basetime, pingt *p)
                peers[i].peer = peer;
                peers[i].basetime = basetime;
                peers[i].timestamp = TIME;
                peers[i].peer = peer;
                peers[i].basetime = basetime;
                peers[i].timestamp = TIME;

-               peers[i].uptodate = !p->undef;
+               peers[i].uptodate = !p.undef;

                if (i == num_peers)
                        ++num_peers;
 
                log(1,0,0,0, "Added %s as a new peer. Now %d peers\n", inet_toa(peer), num_peers);
        }
 
                if (i == num_peers)
                        ++num_peers;
 
                log(1,0,0,0, "Added %s as a new peer. Now %d peers\n", inet_toa(peer), num_peers);
        }
 

-       if (peers[i].uptodate)
-       {
-#ifdef BGP
-               /* drop routes if we've now got a peer */
-               if (config->cluster_iam_master && bgp_configured && !have_peers)
-                       bgp_enable_routing(0);
-#endif /* BGP */
-               have_peers = 1;
-       }
-       else if (config->cluster_iam_master)
-       {
-               config->cluster_iam_uptodate = 0; // increase heart-rate...
-       }
-
-

        return 1;
 }
 
        return 1;
 }
 


@@ -1316,7 +1310,7 @@ int processcluster(char * data, int size, u32 addr)
 
        switch (type) {
        case C_PING:    // Update the peers table.
 
        switch (type) {
        case C_PING:    // Update the peers table.

-               return cluster_add_peer(addr, more, (pingt*)p);
+               return cluster_add_peer(addr, more, (pingt*)p, s);

 
        case C_LASTSEEN:        // Catch up a slave (slave missed a packet).
                return cluster_catchup_slave(more, addr);
 
        case C_LASTSEEN:        // Catch up a slave (slave missed a packet).
                return cluster_catchup_slave(more, addr);