2 * Copyright 2000, International Business Machines Corporation and others.
5 * This software has been released under the terms of the IBM Public
6 * License. For details, see the LICENSE file in the top-level source
7 * directory or online at http://www.openafs.org/dl/license10.html
10 #include <afs/param.h>
11 #include <sys/types.h>
18 #include <sys/socket.h>
19 #include <netinet/in.h>
26 #include <rx/rx_multi.h>
27 #include <afs/cellconfig.h>
29 #include <afs/afsutil.h>
30 #include <afs/netutils.h>
33 #define UBIK_INTERNALS
37 /* statics used to determine if we're the sync site */
38 static afs_int32 syncSiteUntil = 0; /* valid only if amSyncSite */
39 int ubik_amSyncSite = 0; /* flag telling if I'm sync site */
40 static nServers; /* total number of servers */
41 static char amIMagic=0; /* is this host the magic host */
42 char amIClone=0; /* is this a clone which doesn't vote */
43 static char ubik_singleServer = 0;
44 extern struct rx_securityClass *rxnull_NewClientSecurityObject();
45 int (*ubik_CRXSecurityProc)();
46 char *ubik_CRXSecurityRock;
47 afs_int32 ubikSecIndex;
48 struct rx_securityClass *ubikSecClass;
51 /* Module responsible for both deciding if we're currently the sync site,
52 * and keeping collecting votes so as to stay sync site.
54 * The basic module contacts all of the servers it can, trying to get them to vote
55 * for this server for sync site. The vote request message (called a beacon message)
56 * also specifies until which time this site claims to be the sync site, if at all, thus enabling
57 * receiving sites to know how long the sync site guarantee is made for.
59 * Each of these beacon messages is thus both a declaration of how long this site will
60 * remain sync site, and an attempt to extend that time by collecting votes for a later
61 * sync site extension.
63 * The voting module is responsible for choosing a reasonable time until which it promises
64 * not to vote for someone else. This parameter (BIG seconds) is not actually passed in
65 * the interface (perhaps it should be?) but is instead a compile time constant that both
68 * The beacon and vote modules work intimately together; the vote module decides how long
69 * it should promise the beacon module its vote, and the beacon module takes all of these
70 * votes and decides for how long it is the synchronization site.
73 /* procedure called from debug rpc call to get this module's state for debugging */
75 register struct ubik_debug *aparm; {
76 /* fill in beacon's state fields in the ubik_debug structure */
77 aparm->syncSiteUntil = syncSiteUntil;
78 aparm->nServers = nServers;
81 /* procedure that determines whether this site has enough current votes to remain sync site.
82 * called from higher-level modules (everything but the vote module).
84 * If we're the sync site, check that our guarantees, obtained by the ubeacon_Interact
85 * light-weight process, haven't expired. We're sync site as long as a majority of the
86 * servers in existence have promised us unexpired guarantees. The variable ubik_syncSiteUntil
87 * contains the time at which the latest of the majority of the sync site guarantees expires
88 * (if the variable ubik_amSyncSite is true)
89 * This module also calls up to the recovery module if it thinks that the recovery module
90 * may have to pick up a new database (which offucr sif we lose the sync site votes).
92 ubeacon_AmSyncSite() {
93 register afs_int32 now;
94 register afs_int32 rcode;
96 /* special case for fast startup */
97 if (nServers == 1 && !amIClone) {
98 return 1; /* one guy is always the sync site */
101 if (ubik_amSyncSite == 0 || amIClone) rcode = 0; /* if I don't think I'm the sync site, say so */
103 now = FT_ApproxTime();
104 if (syncSiteUntil <= now) { /* if my votes have expired, say so */
105 if (ubik_amSyncSite) ubik_dprint("Ubik: I am no longer the sync site\n");
110 rcode = 1; /* otherwise still have the required votes */
113 if (rcode == 0) urecovery_ResetState(); /* force recovery to re-execute */
114 ubik_dprint("beacon: amSyncSite is %d\n", rcode);
118 /* setup server list; called with two parms, first is my address, second is list of other servers
119 * called only at initialization to set up the list of servers to contact for votes. Just creates
120 * the server structure. Note that there are two connections in every server structure, one for
121 * vote calls (which must always go through quickly) and one for database operations, which
122 * are subject to waiting for locks. If we used only one, the votes would sometimes get
123 * held up behind database operations, and the sync site guarantees would timeout
124 * even though the host would be up for communication.
126 * The "magic" host is the one with the lowest internet address. It is
127 * magic because its vote counts epsilon more than the others. This acts
128 * as a tie-breaker when we have an even number of hosts in the system.
129 * For example, if the "magic" host is up in a 2 site system, then it
130 * is sync site. Without the magic host hack, if anyone crashed in a 2
131 * site system, we'd be out of business.
133 ubeacon_InitServerListByInfo(ame, info, clones)
135 struct afsconf_cell *info;
140 code = ubeacon_InitServerListCommon(ame, info, clones, 0);
144 ubeacon_InitServerList(ame, aservers)
146 register afs_int32 aservers[];
150 code = ubeacon_InitServerListCommon(ame, (struct afsconf_cell *)0, 0,
155 ubeacon_InitServerListCommon(ame, info, clones, aservers)
157 struct afsconf_cell *info;
159 register afs_int32 aservers[];
161 register struct ubik_server *ts;
163 register afs_int32 servAddr;
164 register afs_int32 i, code;
166 struct ubik_server *magicServer;
168 /* verify that the addresses passed in are correct */
169 if (code = verifyInterfaceAddress(&ame, info, aservers))
172 /* get the security index to use, if we can */
173 if (ubik_CRXSecurityProc) {
174 i = (*ubik_CRXSecurityProc)(ubik_CRXSecurityRock, &ubikSecClass, &ubikSecIndex);
178 /* don't have sec module yet */
180 ubikSecClass = rxnull_NewClientSecurityObject();
182 magicHost = ntohl(ame); /* do comparisons in host order */
183 magicServer = (struct ubik_server *) 0;
186 for (i = 0; i < info->numServers; i++) {
187 if (ntohl((afs_uint32) info->hostAddr[i].sin_addr.s_addr) ==
188 ntohl((afs_uint32) ame)) {
197 for (i = 0; i < info->numServers; i++) {
198 if (i == me) continue;
199 ts = (struct ubik_server *) malloc(sizeof(struct ubik_server));
200 bzero(ts, sizeof(struct ubik_server));
201 ts->next = ubik_servers;
203 ts->addr[0] = info->hostAddr[i].sin_addr.s_addr;
208 ntohl((afs_uint32) ts->addr[0]) < (afs_uint32) magicHost) {
209 magicHost = ntohl(ts->addr[0]);
215 ts->vote_rxcid = rx_NewConnection(info->hostAddr[i].sin_addr.s_addr,
218 ubikSecClass, ubikSecIndex);
220 ts->disk_rxcid = rx_NewConnection(info->hostAddr[i].sin_addr.s_addr,
222 DISK_SERVICE_ID, ubikSecClass,
228 while (servAddr = *aservers++) {
229 if (i >= MAXSERVERS) return UNHOSTS; /* too many hosts */
230 ts = (struct ubik_server *) malloc(sizeof(struct ubik_server));
231 bzero(ts, sizeof(struct ubik_server));
232 ts->next = ubik_servers;
234 ts->addr[0] = servAddr; /* primary address in net byte order */
235 ts->vote_rxcid = rx_NewConnection(servAddr, ubik_callPortal,
237 ubikSecClass, ubikSecIndex); /* for vote reqs */
238 ts->disk_rxcid = rx_NewConnection(servAddr, ubik_callPortal,
239 DISK_SERVICE_ID, ubikSecClass,
240 ubikSecIndex); /* for disk reqs */
241 ts->isClone = 0; /* don't know about clones */
243 if (ntohl((afs_uint32) servAddr) < (afs_uint32) magicHost) {
244 magicHost = ntohl(servAddr);
250 if (magicServer) magicServer->magic = 1; /* remember for when counting votes */
252 if (!amIClone && !magicServer) amIMagic = 1;
255 ++nServers; /* count this server as well as the remotes */
257 nServers = i+1; /* count this server as well as the remotes */
259 ubik_quorum = (nServers>>1)+1; /* compute the majority figure */
260 /* send addrs to all other servers */
261 code = updateUbikNetworkAddress(ubik_host);
265 /* Shoud we set some defaults for RX??
267 r_nRetries = (RPCTIMEOUT/r_retryInterval);
270 if (!ubik_servers) /* special case 1 server */
271 ubik_singleServer = 1;
272 if (nServers == 1 && !amIClone) {
273 ubik_amSyncSite = 1; /* let's start as sync site */
274 syncSiteUntil = 0x7fffffff; /* and be it quite a while */
277 if (nServers == 1) /* special case 1 server */
278 ubik_singleServer = 1;
281 if (ubik_singleServer) {
282 if (!ubik_amSyncSite) ubik_dprint("Ubik: I am the sync site - 1 server\n");
284 syncSiteUntil = 0x7fffffff; /* quite a while */
289 /* main lwp loop for code that sends out beacons. This code only runs while
290 * we're sync site or we want to be the sync site. It runs in its very own light-weight
294 register afs_int32 code;
296 struct rx_connection *connections[MAXSERVERS];
297 struct ubik_server *servers[MAXSERVERS];
298 register afs_int32 i;
299 register struct ubik_server *ts;
300 afs_int32 temp, yesVotes, lastWakeupTime, oldestYesVote, syncsite;
301 struct ubik_tid ttid;
304 /* loop forever getting votes */
305 lastWakeupTime = 0; /* keep track of time we last started a vote collection */
308 /* don't wakeup more than every POLLTIME seconds */
309 temp = (lastWakeupTime + POLLTIME) - FT_ApproxTime();
310 /* don't sleep if last collection phase took too long (probably timed someone out ) */
312 if (temp > POLLTIME) temp = POLLTIME;
315 code = IOMGR_Select(0, 0, 0, 0, &tt);
319 lastWakeupTime = FT_ApproxTime(); /* started a new collection phase */
321 if (ubik_singleServer) continue; /* special-case 1 server for speedy startup */
323 if (!uvote_ShouldIRun()) continue; /* if voter has heard from a better candidate than us, don't bother running */
325 /* otherwise we should run for election, or we're the sync site (and have already won);
326 send out the beacon packets */
327 /* build list of all up hosts (noticing dead hosts are running again
328 is a task for the recovery module, not the beacon module), and
329 prepare to send them an r multi-call containing the beacon message */
330 i = 0; /* collect connections */
331 for(ts = ubik_servers; ts; ts=ts->next) {
332 if (ts->up && ts->addr[0] != ubik_host[0]) {
334 connections[i++] = ts->vote_rxcid;
337 servers[i] = (struct ubik_server *) 0; /* end of list */
338 /* note that we assume in the vote module that we'll always get at least BIGTIME
339 seconds of vote from anyone who votes for us, which means we can conservatively
340 assume we'll be fine until SMALLTIME seconds after we start collecting votes */
341 /* this next is essentially an expansion of rgen's ServBeacon routine */
343 ttid.epoch = ubik_epochTime;
344 if (ubik_dbase->flags & DBWRITING) {
346 * if a write is in progress, we have to send the writeTidCounter
347 * which holds the tid counter of the write transaction , and not
348 * send the tidCounter value which holds the tid counter of the
351 ttid.counter = ubik_dbase->writeTidCounter;
354 ttid.counter = ubik_dbase->tidCounter+1;
356 /* now analyze return codes, counting up our votes */
357 yesVotes = 0; /* count how many to ensure we have quorum */
358 oldestYesVote = 0x3fffffff; /* time quorum expires */
359 syncsite= ubeacon_AmSyncSite();
360 startTime = FT_ApproxTime();
362 * Don't waste time using mult Rx calls if there are no connections out there
365 multi_Rx(connections, i) {
366 multi_VOTE_Beacon(syncsite, startTime, &ubik_dbase->version, &ttid);
367 temp = FT_ApproxTime(); /* now, more or less */
368 ts = servers[multi_i];
369 ts->lastBeaconSent = temp;
371 /* note that the vote time (the return code) represents the time
372 the vote was computed, *not* the time the vote expires. We compute
373 the latter down below if we got enough votes to go with */
375 ts->lastVoteTime = code;
376 if (code < oldestYesVote) oldestYesVote = code;
380 if (ts->magic) yesVotes++; /* the extra epsilon */
381 ts->up = 1; /* server is up (not really necessary: recovery does this for real) */
382 ts->beaconSinceDown = 1;
383 ubik_dprint("yes vote from host %s\n",afs_inet_ntoa(ts->addr[0]));
385 else if (code == 0) {
386 ts->lastVoteTime = temp;
388 ts->beaconSinceDown = 1;
389 ubik_dprint("no vote from %s\n", afs_inet_ntoa(ts->addr[0]));
393 ts->beaconSinceDown = 0;
394 urecovery_LostServer();
395 ubik_dprint("time out from %s\n", afs_inet_ntoa(ts->addr[0]));
399 /* now call our own voter module to see if we'll vote for ourself. Note that
400 the same restrictions apply for our voting for ourself as for our voting
402 i = SVOTE_Beacon((struct rx_connection *) 0, ubeacon_AmSyncSite(), startTime, &ubik_dbase->version, &ttid);
405 if (amIMagic) yesVotes++; /* extra epsilon */
406 if (i < oldestYesVote) oldestYesVote = i;
409 /* now decide if we have enough votes to become sync site.
410 Note that we can still get enough votes even if we didn't for ourself. */
411 if (yesVotes > nServers) { /* yesVotes is bumped by 2 or 3 for each site */
412 if (!ubik_amSyncSite) ubik_dprint("Ubik: I am the sync site\n");
414 syncSiteUntil = oldestYesVote + SMALLTIME;
415 LWP_NoYieldSignal(&ubik_amSyncSite);
418 if (ubik_amSyncSite) ubik_dprint("Ubik: I am no longer the sync site\n");
420 urecovery_ResetState(); /* tell recovery we're no longer the sync site */
427 * Input Param : ame is the pointer to my IP address specified in the
428 * CellServDB file. aservers is an array containing IP
429 * addresses of remote ubik servers. The array is
430 * terminated by a zero address.
432 * Algorithm : Verify that my IP addresses 'ame' does actually exist
433 * on this machine. If any of my IP addresses are there
434 * in the remote server list 'aserver', remove them from
435 * this list. Update global variable ubik_host[] with
438 * Return Values : 0 on success, non-zero on failure
440 static verifyInterfaceAddress(ame, info, aservers)
441 struct afsconf_cell *info;
442 afs_uint32 aservers[]; /* list of all possible server addresses */
443 afs_uint32 *ame; /* one of my interface addr in net byte order */
445 afs_uint32 myAddr[UBIK_MAX_INTERFACE_ADDR], *servList, tmpAddr;
446 int count, index, found, i, j, totalServers, start, end;
449 totalServers = info->numServers;
450 else { /* count the number of servers */
451 for ( totalServers=0, servList = aservers; *servList; servList++)
456 /* for now use getaddr(). use getAllAddr when implemented */
457 myAddr[0] = rxi_getaddr();
458 count = (myAddr[0] != 0);
460 if(AFSDIR_SERVER_NETRESTRICT_FILEPATH || AFSDIR_SERVER_NETINFO_FILEPATH) {
462 * Find addresses we are supposed to register as per the netrestrict file
463 * if it exists, else just register all the addresses we find on this
464 * host as returned by rx_getAllAddr (in NBO)
467 count=parseNetFiles(myAddr,NULL,NULL,UBIK_MAX_INTERFACE_ADDR,
468 reason,AFSDIR_SERVER_NETINFO_FILEPATH,
469 AFSDIR_SERVER_NETRESTRICT_FILEPATH);
471 ubik_print("ubik: Can't register any valid addresses:%s\n",reason);
472 ubik_print("Aborting..\n");
477 /* get all my interface addresses in net byte order */
478 count = rx_getAllAddr(myAddr, UBIK_MAX_INTERFACE_ADDR);
482 if ( count <= 0 ) /* no address found */
484 ubik_print("ubik: No network addresses found, aborting..");
488 /* verify that the My-address passed in by ubik is correct */
489 for ( j=0, found = 0; j < count; j++)
491 if ( *ame == myAddr[j] ) /* both in net byte order */
500 ubik_print("ubik: primary address %s does not exist\n",
501 afs_inet_ntoa(*ame));
505 /* if any of my addresses are there in serverList, then
506 ** use that as my primary addresses : the higher level
507 ** application screwed up in dealing with multihomed concepts
509 for ( j=0, found = 0; j < count; j++)
511 for ( i=0; i < totalServers; i++) {
513 tmpAddr = ntohl((afs_uint32) info->hostAddr[i].sin_addr.s_addr);
515 tmpAddr = aservers[i];
516 if ( myAddr[j] == tmpAddr) {
525 ubik_print("Using %s as my primary address\n", afs_inet_ntoa(*ame) );
528 /* get rid of servers which were purged because all
529 ** those interface addresses are myself
531 for ( start=0, end=totalServers-1; (start<end) ; start++, end--)
533 /* find the first zero entry from the beginning */
534 for ( ; (start < end) && ( aservers[start] ); start++);
536 /* find the last non-zero entry from the end */
537 for ( ; (end >= 0) && ( !aservers[end] ); end-- );
539 /* if there is nothing more to purge, exit from loop */
540 if ( start >= end ) break;
543 aservers[start] = aservers[end];
544 aservers[end] = 0; /* this entry was moved */
548 /* update all my addresses in ubik_host in such a way
549 ** that ubik_host[0] has the primary address
552 for ( j=0, i=1; j < count; j++)
553 if ( *ame != myAddr[j] )
554 ubik_host[i++] = myAddr[j];
556 return 0; /* return success */
561 * Input Param : ubik_host is an array containing all my IP addresses.
563 * Algorithm : Do an RPC to all remote ubik servers infroming them
564 * about my IP addresses. Get their IP addresses and
565 * update my linked list of ubik servers 'ubik_servers'
567 * Return Values : 0 on success, non-zero on failure
570 updateUbikNetworkAddress(ubik_host)
571 afs_uint32 ubik_host[UBIK_MAX_INTERFACE_ADDR];
573 int j, count, found, index, code = 0;
574 UbikInterfaceAddr inAddr, outAddr;
575 struct rx_connection *conns[MAXSERVERS];
576 struct ubik_server *ts, *server[MAXSERVERS];
579 for ( count = 0, ts=ubik_servers; ts; count++, ts = ts->next )
581 conns[count] = ts->disk_rxcid;
586 /* inform all other servers only if there are more than one
587 database servers in the cell */
591 for ( j=0; j < UBIK_MAX_INTERFACE_ADDR; j++)
592 inAddr.hostAddr[j] = ntohl(ubik_host[j]);
595 /* do the multi-RX RPC to all other servers */
596 multi_Rx(conns, count) {
597 multi_DISK_UpdateInterfaceAddr(&inAddr, &outAddr);
598 ts = server[multi_i]; /* reply received from this server */
599 if ( !multi_error ) {
600 if ( ts->addr[0] != htonl(outAddr.hostAddr[0]) ) {
602 strcpy(buffer, (char*)afs_inet_ntoa(ts->addr[0]));
603 ubik_print("ubik:Two primary addresses for same server \
604 %s %s\n", buffer, afs_inet_ntoa(htonl(outAddr.hostAddr[0])));
607 for ( j=1; j < UBIK_MAX_INTERFACE_ADDR; j++)
608 ts->addr[j] = htonl(outAddr.hostAddr[j]);
611 else if ( multi_error == RXGEN_OPCODE ) {/* pre 3.5 remote server */
612 ubik_print("ubik server %s does not support UpdateInterfaceAddr RPC\n", afs_inet_ntoa(ts->addr[0]));
614 else if ( multi_error == UBADHOST ) {
615 code = UBADHOST; /* remote CellServDB inconsistency */
616 ubik_print("Inconsistent Cell Info on server: ");
617 for ( j=0; j < UBIK_MAX_INTERFACE_ADDR && ts->addr[j]; j++)
618 printf("%s ", afs_inet_ntoa(ts->addr[j]));
620 fflush(stdout); fflush(stderr);
623 ts->up= 0; /* mark the remote server as down */