MEDIUM: peers: Fix a peer stick-tables synchronization issue.

During the stick-table teaching process which occurs at reloading/restart time,
expiration dates of stick-tables entries were not synchronized between peers.

This patch adds two new stick-table messages to provide such a synchronization feature.

As these new messages are not supported by older haproxy peers protocol versions,
this patch increments peers protol version, from 2.0 to 2.1, to help in detecting/supporting
such older peers protocol implementations so that new versions might still be able
to transparently communicate with a newer one.

[wt: technically speaking it would be nice to have this backported into 1.6
 as some people who reload often are affected by this design limitation, but
 it's not a totally transparent change that may make certain users feel
 reluctant to upgrade older versions. Let's let it cook in 1.7 first and
 decide later]
This commit is contained in:
Frdric Lcaille 2016-10-12 17:30:30 +02:00 committed by Willy Tarreau
parent ad9a7e9770
commit 523cc9e858
3 changed files with 149 additions and 21 deletions

View File

@ -42,6 +42,10 @@ int stktable_init(struct stktable *t);
int stktable_parse_type(char **args, int *idx, unsigned long *type, size_t *key_size);
struct stksess *stktable_get_entry(struct stktable *table, struct stktable_key *key);
struct stksess *stktable_store(struct stktable *t, struct stksess *ts, int local);
struct stksess *stktable_store_with_exp(struct stktable *t, struct stksess *ts,
int local, int expire);
struct stksess *stktable_touch_with_exp(struct stktable *t, struct stksess *ts,
int local, int expire);
struct stksess *stktable_touch(struct stktable *t, struct stksess *ts, int local);
struct stksess *stktable_lookup(struct stktable *t, struct stksess *ts);
struct stksess *stktable_lookup_key(struct stktable *t, struct stktable_key *key);

View File

@ -23,6 +23,7 @@
#include <common/compat.h>
#include <common/config.h>
#include <common/time.h>
#include <common/standard.h>
#include <types/global.h>
#include <types/listener.h>
@ -80,6 +81,7 @@
#define PEER_F_TEACH_COMPLETE 0x00000010 /* All that we know already taught to current peer, used only for a local peer */
#define PEER_F_LEARN_ASSIGN 0x00000100 /* Current peer was assigned for a lesson */
#define PEER_F_LEARN_NOTUP2DATE 0x00000200 /* Learn from peer finished but peer is not up to date */
#define PEER_F_DWNGRD 0x80000000 /* When this flag is enabled, we must downgrade the supported version announced during peer sessions. */
#define PEER_TEACH_RESET ~(PEER_F_TEACH_PROCESS|PEER_F_TEACH_FINISHED) /* PEER_F_TEACH_COMPLETE should never be reset */
#define PEER_LEARN_RESET ~(PEER_F_LEARN_ASSIGN|PEER_F_LEARN_NOTUP2DATE)
@ -124,6 +126,8 @@ enum {
PEER_MSG_STKT_DEFINE,
PEER_MSG_STKT_SWITCH,
PEER_MSG_STKT_ACK,
PEER_MSG_STKT_UPDATE_TIMED,
PEER_MSG_STKT_INCUPDATE_TIMED,
};
/**********************************/
@ -163,6 +167,9 @@ enum {
#define PEER_SESS_SC_ERRPEER 504 /* unknown peer */
#define PEER_SESSION_PROTO_NAME "HAProxyS"
#define PEER_MAJOR_VER 2
#define PEER_MINOR_VER 1
#define PEER_DWNGRD_MINOR_VER 0
struct peers *peers = NULL;
static void peer_session_forceshutdown(struct stream * stream);
@ -230,6 +237,26 @@ uint64_t intdecode(char **str, char *end) {
return i;
}
/* Set the stick-table UPDATE message type byte at <msg_type> address,
* depending on <use_identifier> and <use_timed> boolean parameters.
* Always successful.
*/
static inline void peer_set_update_msg_type(char *msg_type, int use_identifier, int use_timed)
{
if (use_timed) {
if (use_identifier)
*msg_type = PEER_MSG_STKT_UPDATE_TIMED;
else
*msg_type = PEER_MSG_STKT_INCUPDATE_TIMED;
}
else {
if (use_identifier)
*msg_type = PEER_MSG_STKT_UPDATE;
else
*msg_type = PEER_MSG_STKT_INCUPDATE;
}
}
/*
* This prepare the data update message on the stick session <ts>, <st> is the considered
* stick table.
@ -237,7 +264,7 @@ uint64_t intdecode(char **str, char *end) {
* If function returns 0, the caller should consider we were unable to encode this message (TODO:
* check size)
*/
static int peer_prepare_updatemsg(struct stksess *ts, struct shared_table *st, char *msg, size_t size, int use_identifier)
static int peer_prepare_updatemsg(struct stksess *ts, struct shared_table *st, char *msg, size_t size, int use_identifier, int use_timed)
{
uint32_t netinteger;
unsigned short datalen;
@ -261,6 +288,12 @@ static int peer_prepare_updatemsg(struct stksess *ts, struct shared_table *st, c
cursor += sizeof(netinteger);
}
if (use_timed) {
netinteger = htonl(tick_remain(now_ms, ts->expire));
memcpy(cursor, &netinteger, sizeof(netinteger));
cursor += sizeof(netinteger);
}
/* encode the key */
if (st->table->type == SMP_T_STR) {
int stlen = strlen((char *)ts->key.key);
@ -324,11 +357,7 @@ static int peer_prepare_updatemsg(struct stksess *ts, struct shared_table *st, c
/* prepare message header */
msg[0] = PEER_MSG_CLASS_STICKTABLE;
if (use_identifier)
msg[1] = PEER_MSG_STKT_UPDATE;
else
msg[1] = PEER_MSG_STKT_INCUPDATE;
peer_set_update_msg_type(&msg[1], use_identifier, use_timed);
cursor = &msg[2];
intencode(datalen, &cursor);
@ -477,6 +506,34 @@ static void peer_session_release(struct appctx *appctx)
}
}
/* Retrieve the major and minor versions of peers protocol
* announced by a remote peer. <str> is a null-terminated
* string with the following format: "<maj_ver>.<min_ver>".
*/
static int peer_get_version(const char *str,
unsigned int *maj_ver, unsigned int *min_ver)
{
unsigned int majv, minv;
const char *pos, *saved;
const char *end;
saved = pos = str;
end = str + strlen(str);
majv = read_uint(&pos, end);
if (saved == pos || *pos++ != '.')
return -1;
saved = pos;
minv = read_uint(&pos, end);
if (saved == pos || pos != end)
return -1;
*maj_ver = majv;
*min_ver = minv;
return 0;
}
/*
* IO Handler to handle message exchance with a peer
@ -488,9 +545,12 @@ static void peer_io_handler(struct appctx *appctx)
struct peers *curpeers = strm_fe(s)->parent;
int reql = 0;
int repl = 0;
size_t proto_len = strlen(PEER_SESSION_PROTO_NAME);
unsigned int maj_ver, min_ver;
while (1) {
switchstate:
maj_ver = min_ver = (unsigned int)-1;
switch(appctx->st0) {
case PEER_SESS_ST_ACCEPT:
appctx->ctx.peers.ptr = NULL;
@ -515,13 +575,16 @@ switchstate:
bo_skip(si_oc(si), reql);
/* test version */
if (strcmp(PEER_SESSION_PROTO_NAME " 2.0", trash.str) != 0) {
/* test protocol */
if (strncmp(PEER_SESSION_PROTO_NAME " ", trash.str, proto_len + 1) != 0) {
appctx->st0 = PEER_SESS_ST_EXIT;
appctx->st1 = PEER_SESS_SC_ERRPROTO;
goto switchstate;
}
if (peer_get_version(trash.str + proto_len + 1, &maj_ver, &min_ver) == -1 ||
maj_ver != PEER_MAJOR_VER || min_ver > PEER_MINOR_VER) {
appctx->st0 = PEER_SESS_ST_EXIT;
appctx->st1 = PEER_SESS_SC_ERRVERSION;
/* test protocol */
if (strncmp(PEER_SESSION_PROTO_NAME " ", trash.str, strlen(PEER_SESSION_PROTO_NAME)+1) != 0)
appctx->st1 = PEER_SESS_SC_ERRPROTO;
goto switchstate;
}
@ -608,6 +671,14 @@ switchstate:
}
peer_session_forceshutdown(curpeer->stream);
}
if (maj_ver != (unsigned int)-1 && min_ver != (unsigned int)-1) {
if (min_ver == PEER_DWNGRD_MINOR_VER) {
curpeer->flags |= PEER_F_DWNGRD;
}
else {
curpeer->flags &= ~PEER_F_DWNGRD;
}
}
curpeer->stream = s;
curpeer->appctx = appctx;
appctx->ctx.peers.ptr = curpeer;
@ -674,7 +745,9 @@ switchstate:
/* Send headers */
repl = snprintf(trash.str, trash.size,
PEER_SESSION_PROTO_NAME " 2.0\n%s\n%s %d %d\n",
PEER_SESSION_PROTO_NAME " %u.%u\n%s\n%s %d %d\n",
PEER_MAJOR_VER,
(curpeer->flags & PEER_F_DWNGRD) ? PEER_DWNGRD_MINOR_VER : PEER_MINOR_VER,
curpeer->id,
localpeer,
(int)getpid(),
@ -762,6 +835,8 @@ switchstate:
}
else {
if (curpeer->statuscode == PEER_SESS_SC_ERRVERSION)
curpeer->flags |= PEER_F_DWNGRD;
/* Status code is not success, abort */
appctx->st0 = PEER_SESS_ST_END;
goto switchstate;
@ -1007,9 +1082,12 @@ switchstate:
}
else if (msg_head[1] == PEER_MSG_STKT_UPDATE
|| msg_head[1] == PEER_MSG_STKT_INCUPDATE) {
|| msg_head[1] == PEER_MSG_STKT_INCUPDATE
|| msg_head[1] == PEER_MSG_STKT_UPDATE_TIMED
|| msg_head[1] == PEER_MSG_STKT_INCUPDATE_TIMED) {
struct shared_table *st = curpeer->remote_table;
uint32_t update;
int expire;
unsigned int data_type;
void *data_ptr;
@ -1017,7 +1095,10 @@ switchstate:
if (!st)
goto ignore_msg;
if (msg_head[1] == PEER_MSG_STKT_UPDATE) {
expire = MS_TO_TICKS(st->table->expire);
if (msg_head[1] == PEER_MSG_STKT_UPDATE ||
msg_head[1] == PEER_MSG_STKT_UPDATE_TIMED) {
if (msg_len < sizeof(update)) {
/* malformed message */
appctx->st0 = PEER_SESS_ST_ERRPROTO;
@ -1031,6 +1112,19 @@ switchstate:
st->last_get++;
}
if (msg_head[1] == PEER_MSG_STKT_UPDATE_TIMED ||
msg_head[1] == PEER_MSG_STKT_INCUPDATE_TIMED) {
size_t expire_sz = sizeof expire;
if (msg_cur + expire_sz > msg_end) {
appctx->st0 = PEER_SESS_ST_ERRPROTO;
goto switchstate;
}
memcpy(&expire, msg_cur, expire_sz);
msg_cur += expire_sz;
expire = ntohl(expire);
}
newts = stksess_new(st->table, NULL);
if (!newts)
goto ignore_msg;
@ -1086,7 +1180,7 @@ switchstate:
ts = stktable_lookup(st->table, newts);
if (ts) {
/* the entry already exist, we can free ours */
stktable_touch(st->table, ts, 0);
stktable_touch_with_exp(st->table, ts, 0, tick_add(now_ms, expire));
stksess_free(st->table, newts);
newts = NULL;
}
@ -1094,7 +1188,7 @@ switchstate:
struct eb32_node *eb;
/* create new entry */
ts = stktable_store(st->table, newts, 0);
ts = stktable_store_with_exp(st->table, newts, 0, tick_add(now_ms, expire));
newts = NULL; /* don't reuse it */
ts->upd.key= (++st->table->update)+(2147483648U);
@ -1343,7 +1437,7 @@ incomplete:
}
ts = eb32_entry(eb, struct stksess, upd);
msglen = peer_prepare_updatemsg(ts, st, trash.str, trash.size, new_pushed);
msglen = peer_prepare_updatemsg(ts, st, trash.str, trash.size, new_pushed, 0);
if (!msglen) {
/* internal error: message does not fit in trash */
appctx->st0 = PEER_SESS_ST_END;
@ -1404,6 +1498,7 @@ incomplete:
while (1) {
uint32_t msglen;
struct stksess *ts;
int use_timed;
/* push local updates */
if (!eb) {
@ -1415,7 +1510,8 @@ incomplete:
}
ts = eb32_entry(eb, struct stksess, upd);
msglen = peer_prepare_updatemsg(ts, st, trash.str, trash.size, new_pushed);
use_timed = !(curpeer->flags & PEER_F_DWNGRD);
msglen = peer_prepare_updatemsg(ts, st, trash.str, trash.size, new_pushed, use_timed);
if (!msglen) {
/* internal error: message does not fit in trash */
appctx->st0 = PEER_SESS_ST_END;
@ -1473,6 +1569,7 @@ incomplete:
while (1) {
uint32_t msglen;
struct stksess *ts;
int use_timed;
/* push local updates */
if (!eb || eb->key > st->teaching_origin) {
@ -1481,7 +1578,8 @@ incomplete:
}
ts = eb32_entry(eb, struct stksess, upd);
msglen = peer_prepare_updatemsg(ts, st, trash.str, trash.size, new_pushed);
use_timed = !(curpeer->flags & PEER_F_DWNGRD);
msglen = peer_prepare_updatemsg(ts, st, trash.str, trash.size, new_pushed, use_timed);
if (!msglen) {
/* internal error: message does not fit in trash */
appctx->st0 = PEER_SESS_ST_END;

View File

@ -244,10 +244,11 @@ struct stksess *stktable_lookup(struct stktable *t, struct stksess *ts)
/* Update the expiration timer for <ts> but do not touch its expiration node.
* The table's expiration timer is updated if set.
*/
struct stksess *stktable_touch(struct stktable *t, struct stksess *ts, int local)
struct stksess *stktable_touch_with_exp(struct stktable *t, struct stksess *ts,
int local, int expire)
{
struct eb32_node * eb;
ts->expire = tick_add(now_ms, MS_TO_TICKS(t->expire));
ts->expire = expire;
if (t->expire) {
t->exp_task->expire = t->exp_next = tick_first(ts->expire, t->exp_next);
task_queue(t->exp_task);
@ -274,6 +275,17 @@ struct stksess *stktable_touch(struct stktable *t, struct stksess *ts, int local
return ts;
}
/* Update the expiration timer for <ts> but do not touch its expiration node.
* The table's expiration timer is updated if set. The date of expiration coming from
* <t> stick-table configuration.
*/
struct stksess *stktable_touch(struct stktable *t, struct stksess *ts, int local)
{
int expire = tick_add(now_ms, MS_TO_TICKS(t->expire));
return stktable_touch_with_exp(t, ts, local, expire);
}
/* Insert new sticky session <ts> in the table. It is assumed that it does not
* yet exist (the caller must check this). The table's timeout is updated if it
* is set. <ts> is returned.
@ -287,6 +299,20 @@ struct stksess *stktable_store(struct stktable *t, struct stksess *ts, int local
return ts;
}
/* Same function as stktable_store(), but with <expire> as supplementary argument
* to set the date of expiration of <ts> new sticky session thanks to
* stktable_touch_with_exp().
*/
struct stksess *stktable_store_with_exp(struct stktable *t, struct stksess *ts,
int local, int expire)
{
ebmb_insert(&t->keys, &ts->key, t->key_size);
stktable_touch_with_exp(t, ts, local, expire);
ts->exp.key = ts->expire;
eb32_insert(&t->exps, &ts->exp);
return ts;
}
/* Returns a valid or initialized stksess for the specified stktable_key in the
* specified table, or NULL if the key was NULL, or if no entry was found nor
* could be created. The entry's expiration is updated.