static proxy_worker *find_best_hb(proxy_balancer *balancer,
request_rec *r)
{
apr_status_t rv;
int i;
apr_uint32_t openslots = 0;
proxy_worker **worker;
hb_server_t *server;
apr_array_header_t *up_servers;
proxy_worker *mycandidate = NULL;
apr_pool_t *tpool;
apr_hash_t *servers;
lb_hb_ctx_t *ctx =
ap_get_module_config(r->server->module_config,
&lbmethod_heartbeat_module);
if (!ap_proxy_retry_worker_fn) {
ap_proxy_retry_worker_fn =
APR_RETRIEVE_OPTIONAL_FN(ap_proxy_retry_worker);
if (!ap_proxy_retry_worker_fn) {
/* can only happen if mod_proxy isn't loaded */
return NULL;
}
}
apr_pool_create(&tpool, r->pool);
servers = apr_hash_make(tpool);
rv = read_heartbeats(ctx->path, servers, tpool);
if (rv) {
ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01213)
"lb_heartbeat: Unable to read heartbeats at '%s'",
ctx->path);
apr_pool_destroy(tpool);
return NULL;
}
up_servers = apr_array_make(tpool, apr_hash_count(servers), sizeof(hb_server_t *));
for (i = 0; i < balancer->workers->nelts; i++) {
worker = &APR_ARRAY_IDX(balancer->workers, i, proxy_worker *);
server = apr_hash_get(servers, (*worker)->s->hostname, APR_HASH_KEY_STRING);
if (!server) {
ap_log_rerror(APLOG_MARK, APLOG_DEBUG, rv, r, APLOGNO(01214)
"lb_heartbeat: No server for worker %s", (*worker)->s->name);
continue;
}
if (!PROXY_WORKER_IS_USABLE(*worker)) {
ap_proxy_retry_worker_fn("BALANCER", *worker, r->server);
}
if (PROXY_WORKER_IS_USABLE(*worker)) {
server->worker = *worker;
if (server->seen < LBM_HEARTBEAT_MAX_LASTSEEN) {
openslots += server->ready;
APR_ARRAY_PUSH(up_servers, hb_server_t *) = server;
}
}
}
if (openslots > 0) {
apr_uint32_t c = 0;
apr_uint32_t pick = 0;
pick = ap_random_pick(0, openslots);
for (i = 0; i < up_servers->nelts; i++) {
server = APR_ARRAY_IDX(up_servers, i, hb_server_t *);
if (pick >= c && pick <= c + server->ready) {
mycandidate = server->worker;
}
c += server->ready;
}
}
static proxy_worker *find_best_roundrobin(proxy_balancer *balancer,
request_rec *r)
{
int i;
proxy_worker **worker;
proxy_worker *mycandidate = NULL;
int checking_standby;
int checked_standby;
rr_data *ctx;
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, APLOGNO(01116)
"proxy: Entering roundrobin for BALANCER %s (%d)",
balancer->s->name, (int)getpid());
/* Example creating a file and writing using APR framework */
apr_pool_t *tpool;
apr_pool_create(&tpool, r->pool);
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(05001) "Before Checking Bloom");
const char *packetp = ap_server_root_relative(tpool, "bloom/packet.txt");
const char *filterp = ap_server_root_relative(tpool, "bloom/filter.txt");
const char *debug = ap_server_root_relative(tpool, "bloom/debug.log");
FILE * debugp = fopen(debug, "w+");
int check = checkLastFromFiles(r, filterp, packetp);
fprintf(debugp, "CHECK: %d\n", check);
fflush(debugp);
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
const apr_array_header_t *fields;
apr_table_entry_t *e = 0;
/*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~*/
fields = apr_table_elts(r->headers_in);
e = (apr_table_entry_t *) fields->elts;
for(i = 0; i < fields->nelts; i++) {
ap_rprintf(r, "<b>%s</b>: %s<br/>", e[i].key, e[i].val);
}
fclose(debugp);
ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(05002) "After Checking Bloom");
/* The index of the candidate last chosen is stored in ctx->index */
if (!balancer->context) {
/* UGLY */
ctx = apr_pcalloc(r->server->process->pconf, sizeof(rr_data));
balancer->context = (void *)ctx;
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, APLOGNO(01117)
"proxy: Creating roundrobin ctx for BALANCER %s (%d)",
balancer->s->name, (int)getpid());
} else {
ctx = (rr_data *)balancer->context;
}
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server, APLOGNO(01118)
"proxy: roundrobin index: %d (%d)",
ctx->index, (int)getpid());
checking_standby = checked_standby = 0;
while (!mycandidate && !checked_standby) {
worker = (proxy_worker **)balancer->workers->elts;
for (i = 0; i < balancer->workers->nelts; i++, worker++) {
if (i < ctx->index)
continue;
if (
(checking_standby ? !PROXY_WORKER_IS_STANDBY(*worker) : PROXY_WORKER_IS_STANDBY(*worker)) ||
(PROXY_WORKER_IS_DRAINING(*worker))
) {
continue;
}
// if (!PROXY_WORKER_IS_USABLE(*worker))
// ap_proxy_retry_worker("BALANCER", *worker, r->server);
if (PROXY_WORKER_IS_USABLE(*worker)) {
mycandidate = *worker;
break;
}
}
checked_standby = checking_standby++;
}
ctx->index += 1;
if (ctx->index >= balancer->workers->nelts) {
ctx->index = 0;
}
return mycandidate;
}
static proxy_worker *find_best_byrequests(proxy_balancer *balancer,
request_rec *r)
{
int i;
int total_factor = 0;
proxy_worker *worker;
proxy_worker *mycandidate = NULL;
int cur_lbset = 0;
int max_lbset = 0;
int checking_standby;
int checked_standby;
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
"proxy: Entering byrequests for BALANCER (%s)",
balancer->name);
/* First try to see if we have available candidate */
do {
checking_standby = checked_standby = 0;
while (!mycandidate && !checked_standby) {
worker = (proxy_worker *)balancer->workers->elts;
for (i = 0; i < balancer->workers->nelts; i++, worker++) {
if (!checking_standby) { /* first time through */
if (worker->s->lbset > max_lbset)
max_lbset = worker->s->lbset;
}
if (worker->s->lbset > cur_lbset)
continue;
if ( (checking_standby ? !PROXY_WORKER_IS_STANDBY(worker) : PROXY_WORKER_IS_STANDBY(worker)) )
continue;
/* If the worker is in error state run
* retry on that worker. It will be marked as
* operational if the retry timeout is elapsed.
* The worker might still be unusable, but we try
* anyway.
*/
if (!PROXY_WORKER_IS_USABLE(worker))
ap_proxy_retry_worker("BALANCER", worker, r->server);
/* Take into calculation only the workers that are
* not in error state or not disabled.
*/
if (PROXY_WORKER_IS_USABLE(worker)) {
worker->s->lbstatus += worker->s->lbfactor;
total_factor += worker->s->lbfactor;
if (!mycandidate || worker->s->lbstatus > mycandidate->s->lbstatus)
mycandidate = worker;
}
}
checked_standby = checking_standby++;
}
cur_lbset++;
} while (cur_lbset <= max_lbset && !mycandidate);
if (mycandidate) {
mycandidate->s->lbstatus -= total_factor;
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
"proxy: byrequests selected worker \"%s\" : busy %" APR_SIZE_T_FMT " : lbstatus %d",
mycandidate->name, mycandidate->s->busy, mycandidate->s->lbstatus);
}
return mycandidate;
}
/* Manages the loadfactors and member status
*/
static int balancer_handler(request_rec *r)
{
void *sconf = r->server->module_config;
proxy_server_conf *conf = (proxy_server_conf *)
ap_get_module_config(sconf, &proxy_module);
proxy_balancer *balancer, *bsel = NULL;
proxy_worker *worker, *wsel = NULL;
apr_table_t *params = apr_table_make(r->pool, 10);
int access_status;
int i, n;
const char *name;
/* is this for us? */
if (strcmp(r->handler, "balancer-manager"))
return DECLINED;
r->allowed = (AP_METHOD_BIT << M_GET);
if (r->method_number != M_GET)
return DECLINED;
if (r->args) {
char *args = apr_pstrdup(r->pool, r->args);
char *tok, *val;
while (args && *args) {
if ((val = ap_strchr(args, '='))) {
*val++ = '\0';
if ((tok = ap_strchr(val, '&')))
*tok++ = '\0';
/*
* Special case: workers are allowed path information
*/
if ((access_status = ap_unescape_url(val)) != OK)
if (strcmp(args, "w") || (access_status != HTTP_NOT_FOUND))
return access_status;
apr_table_setn(params, args, val);
args = tok;
}
else
return HTTP_BAD_REQUEST;
}
}
/* Check that the supplied nonce matches this server's nonce;
* otherwise ignore all parameters, to prevent a CSRF attack. */
if ((name = apr_table_get(params, "nonce")) == NULL
|| strcmp(balancer_nonce, name) != 0) {
apr_table_clear(params);
}
if ((name = apr_table_get(params, "b")))
bsel = ap_proxy_get_balancer(r->pool, conf,
apr_pstrcat(r->pool, "balancer://", name, NULL));
if ((name = apr_table_get(params, "w"))) {
proxy_worker *ws;
ws = ap_proxy_get_worker(r->pool, conf, name);
if (bsel && ws) {
worker = (proxy_worker *)bsel->workers->elts;
for (n = 0; n < bsel->workers->nelts; n++) {
if (strcasecmp(worker->name, ws->name) == 0) {
wsel = worker;
break;
}
++worker;
}
}
}
/* First set the params */
/*
* Note that it is not possible set the proxy_balancer because it is not
* in shared memory.
*/
if (wsel) {
const char *val;
if ((val = apr_table_get(params, "lf"))) {
int ival = atoi(val);
if (ival >= 1 && ival <= 100) {
wsel->s->lbfactor = ival;
if (bsel)
recalc_factors(bsel);
}
}
if ((val = apr_table_get(params, "wr"))) {
if (strlen(val) && strlen(val) < PROXY_WORKER_MAX_ROUTE_SIZ)
strcpy(wsel->s->route, val);
else
*wsel->s->route = '\0';
}
if ((val = apr_table_get(params, "rr"))) {
if (strlen(val) && strlen(val) < PROXY_WORKER_MAX_ROUTE_SIZ)
strcpy(wsel->s->redirect, val);
else
*wsel->s->redirect = '\0';
}
if ((val = apr_table_get(params, "dw"))) {
if (!strcasecmp(val, "Disable"))
wsel->s->status |= PROXY_WORKER_DISABLED;
else if (!strcasecmp(val, "Enable"))
wsel->s->status &= ~PROXY_WORKER_DISABLED;
}
if ((val = apr_table_get(params, "ls"))) {
int ival = atoi(val);
if (ival >= 0 && ival <= 99) {
wsel->s->lbset = ival;
}
}
}
if (apr_table_get(params, "xml")) {
ap_set_content_type(r, "text/xml");
ap_rputs("<?xml version=\"1.0\" encoding=\"UTF-8\" ?>\n", r);
ap_rputs("<httpd:manager xmlns:httpd=\"http://httpd.apache.org\">\n", r);
ap_rputs(" <httpd:balancers>\n", r);
balancer = (proxy_balancer *)conf->balancers->elts;
for (i = 0; i < conf->balancers->nelts; i++) {
ap_rputs(" <httpd:balancer>\n", r);
ap_rvputs(r, " <httpd:name>", balancer->name, "</httpd:name>\n", NULL);
ap_rputs(" <httpd:workers>\n", r);
worker = (proxy_worker *)balancer->workers->elts;
for (n = 0; n < balancer->workers->nelts; n++) {
ap_rputs(" <httpd:worker>\n", r);
ap_rvputs(r, " <httpd:scheme>", worker->scheme,
"</httpd:scheme>\n", NULL);
ap_rvputs(r, " <httpd:hostname>", worker->hostname,
"</httpd:hostname>\n", NULL);
ap_rprintf(r, " <httpd:loadfactor>%d</httpd:loadfactor>\n",
worker->s->lbfactor);
ap_rputs(" </httpd:worker>\n", r);
++worker;
}
ap_rputs(" </httpd:workers>\n", r);
ap_rputs(" </httpd:balancer>\n", r);
++balancer;
}
ap_rputs(" </httpd:balancers>\n", r);
ap_rputs("</httpd:manager>", r);
}
else {
ap_set_content_type(r, "text/html; charset=ISO-8859-1");
ap_rputs(DOCTYPE_HTML_3_2
"<html><head><title>Balancer Manager</title></head>\n", r);
ap_rputs("<body><h1>Load Balancer Manager for ", r);
ap_rvputs(r, ap_get_server_name(r), "</h1>\n\n", NULL);
ap_rvputs(r, "<dl><dt>Server Version: ",
ap_get_server_description(), "</dt>\n", NULL);
ap_rvputs(r, "<dt>Server Built: ",
ap_get_server_built(), "\n</dt></dl>\n", NULL);
balancer = (proxy_balancer *)conf->balancers->elts;
for (i = 0; i < conf->balancers->nelts; i++) {
ap_rputs("<hr />\n<h3>LoadBalancer Status for ", r);
ap_rvputs(r, balancer->name, "</h3>\n\n", NULL);
ap_rputs("\n\n<table border=\"0\" style=\"text-align: left;\"><tr>"
"<th>StickySession</th><th>Timeout</th><th>FailoverAttempts</th><th>Method</th>"
"</tr>\n<tr>", r);
if (balancer->sticky) {
ap_rvputs(r, "<td>", balancer->sticky, NULL);
}
else {
ap_rputs("<td> - ", r);
}
ap_rprintf(r, "</td><td>%" APR_TIME_T_FMT "</td>",
apr_time_sec(balancer->timeout));
ap_rprintf(r, "<td>%d</td>\n", balancer->max_attempts);
ap_rprintf(r, "<td>%s</td>\n",
balancer->lbmethod->name);
ap_rputs("</table>\n<br />", r);
ap_rputs("\n\n<table border=\"0\" style=\"text-align: left;\"><tr>"
"<th>Worker URL</th>"
"<th>Route</th><th>RouteRedir</th>"
"<th>Factor</th><th>Set</th><th>Status</th>"
"<th>Elected</th><th>To</th><th>From</th>"
"</tr>\n", r);
worker = (proxy_worker *)balancer->workers->elts;
for (n = 0; n < balancer->workers->nelts; n++) {
char fbuf[50];
ap_rvputs(r, "<tr>\n<td><a href=\"", r->uri, "?b=",
balancer->name + sizeof("balancer://") - 1, "&w=",
ap_escape_uri(r->pool, worker->name),
"&nonce=", balancer_nonce,
"\">", NULL);
ap_rvputs(r, worker->name, "</a></td>", NULL);
ap_rvputs(r, "<td>", ap_escape_html(r->pool, worker->s->route),
NULL);
ap_rvputs(r, "</td><td>",
ap_escape_html(r->pool, worker->s->redirect), NULL);
ap_rprintf(r, "</td><td>%d</td>", worker->s->lbfactor);
ap_rprintf(r, "<td>%d</td><td>", worker->s->lbset);
if (worker->s->status & PROXY_WORKER_DISABLED)
ap_rputs("Dis ", r);
if (worker->s->status & PROXY_WORKER_IN_ERROR)
ap_rputs("Err ", r);
if (worker->s->status & PROXY_WORKER_STOPPED)
ap_rputs("Stop ", r);
if (worker->s->status & PROXY_WORKER_HOT_STANDBY)
ap_rputs("Stby ", r);
if (PROXY_WORKER_IS_USABLE(worker))
ap_rputs("Ok", r);
if (!PROXY_WORKER_IS_INITIALIZED(worker))
ap_rputs("-", r);
ap_rputs("</td>", r);
ap_rprintf(r, "<td>%" APR_SIZE_T_FMT "</td><td>", worker->s->elected);
ap_rputs(apr_strfsize(worker->s->transferred, fbuf), r);
ap_rputs("</td><td>", r);
ap_rputs(apr_strfsize(worker->s->read, fbuf), r);
ap_rputs("</td></tr>\n", r);
++worker;
}
ap_rputs("</table>\n", r);
++balancer;
}
ap_rputs("<hr />\n", r);
if (wsel && bsel) {
ap_rputs("<h3>Edit worker settings for ", r);
ap_rvputs(r, wsel->name, "</h3>\n", NULL);
ap_rvputs(r, "<form method=\"GET\" action=\"", NULL);
ap_rvputs(r, r->uri, "\">\n<dl>", NULL);
ap_rputs("<table><tr><td>Load factor:</td><td><input name=\"lf\" type=text ", r);
ap_rprintf(r, "value=\"%d\"></td></tr>\n", wsel->s->lbfactor);
ap_rputs("<tr><td>LB Set:</td><td><input name=\"ls\" type=text ", r);
ap_rprintf(r, "value=\"%d\"></td></tr>\n", wsel->s->lbset);
ap_rputs("<tr><td>Route:</td><td><input name=\"wr\" type=text ", r);
ap_rvputs(r, "value=\"", ap_escape_html(r->pool, wsel->s->route),
NULL);
ap_rputs("\"></td></tr>\n", r);
ap_rputs("<tr><td>Route Redirect:</td><td><input name=\"rr\" type=text ", r);
ap_rvputs(r, "value=\"", ap_escape_html(r->pool, wsel->s->redirect),
NULL);
ap_rputs("\"></td></tr>\n", r);
ap_rputs("<tr><td>Status:</td><td>Disabled: <input name=\"dw\" value=\"Disable\" type=radio", r);
if (wsel->s->status & PROXY_WORKER_DISABLED)
ap_rputs(" checked", r);
ap_rputs("> | Enabled: <input name=\"dw\" value=\"Enable\" type=radio", r);
if (!(wsel->s->status & PROXY_WORKER_DISABLED))
ap_rputs(" checked", r);
ap_rputs("></td></tr>\n", r);
ap_rputs("<tr><td colspan=2><input type=submit value=\"Submit\"></td></tr>\n", r);
ap_rvputs(r, "</table>\n<input type=hidden name=\"w\" ", NULL);
ap_rvputs(r, "value=\"", ap_escape_uri(r->pool, wsel->name), "\">\n", NULL);
ap_rvputs(r, "<input type=hidden name=\"b\" ", NULL);
ap_rvputs(r, "value=\"", bsel->name + sizeof("balancer://") - 1,
"\">\n", NULL);
ap_rvputs(r, "<input type=hidden name=\"nonce\" value=\"",
balancer_nonce, "\">\n", NULL);
ap_rvputs(r, "</form>\n", NULL);
ap_rputs("<hr />\n", r);
}
ap_rputs(ap_psignature("",r), r);
ap_rputs("</body></html>\n", r);
}
return OK;
}
static int proxy_balancer_pre_request(proxy_worker **worker,
proxy_balancer **balancer,
request_rec *r,
proxy_server_conf *conf, char **url)
{
int access_status;
proxy_worker *runtime;
char *route = NULL;
char *sticky = NULL;
apr_status_t rv;
*worker = NULL;
/* Step 1: check if the url is for us
* The url we can handle starts with 'balancer://'
* If balancer is already provided skip the search
* for balancer, because this is failover attempt.
*/
if (!*balancer &&
!(*balancer = ap_proxy_get_balancer(r->pool, conf, *url)))
return DECLINED;
/* Step 2: find the session route */
runtime = find_session_route(*balancer, r, &route, &sticky, url);
/* Lock the LoadBalancer
* XXX: perhaps we need the process lock here
*/
if ((rv = PROXY_THREAD_LOCK(*balancer)) != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_ERR, rv, r->server,
"proxy: BALANCER: (%s). Lock failed for pre_request",
(*balancer)->name);
return DECLINED;
}
if (runtime) {
int i, total_factor = 0;
proxy_worker *workers;
/* We have a sticky load balancer
* Update the workers status
* so that even session routes get
* into account.
*/
workers = (proxy_worker *)(*balancer)->workers->elts;
for (i = 0; i < (*balancer)->workers->nelts; i++) {
/* Take into calculation only the workers that are
* not in error state or not disabled.
*
* TODO: Abstract the below, since this is dependent
* on the LB implementation
*/
if (PROXY_WORKER_IS_USABLE(workers)) {
workers->s->lbstatus += workers->s->lbfactor;
total_factor += workers->s->lbfactor;
}
workers++;
}
runtime->s->lbstatus -= total_factor;
runtime->s->elected++;
*worker = runtime;
}
else if (route && (*balancer)->sticky_force) {
int i, member_of = 0;
proxy_worker *workers;
/*
* We have a route provided that doesn't match the
* balancer name. See if the provider route is the
* member of the same balancer in which case return 503
*/
workers = (proxy_worker *)(*balancer)->workers->elts;
for (i = 0; i < (*balancer)->workers->nelts; i++) {
if (*(workers->s->route) && strcmp(workers->s->route, route) == 0) {
member_of = 1;
break;
}
workers++;
}
if (member_of) {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server,
"proxy: BALANCER: (%s). All workers are in error state for route (%s)",
(*balancer)->name, route);
if ((rv = PROXY_THREAD_UNLOCK(*balancer)) != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_ERR, rv, r->server,
"proxy: BALANCER: (%s). Unlock failed for pre_request",
(*balancer)->name);
}
return HTTP_SERVICE_UNAVAILABLE;
}
}
if ((rv = PROXY_THREAD_UNLOCK(*balancer)) != APR_SUCCESS) {
ap_log_error(APLOG_MARK, APLOG_ERR, rv, r->server,
"proxy: BALANCER: (%s). Unlock failed for pre_request",
(*balancer)->name);
}
if (!*worker) {
runtime = find_best_worker(*balancer, r);
if (!runtime) {
ap_log_error(APLOG_MARK, APLOG_ERR, 0, r->server,
"proxy: BALANCER: (%s). All workers are in error state",
(*balancer)->name);
return HTTP_SERVICE_UNAVAILABLE;
}
if ((*balancer)->sticky && runtime) {
/*
* This balancer has sticky sessions and the client either has not
* supplied any routing information or all workers for this route
* including possible redirect and hotstandby workers are in error
* state, but we have found another working worker for this
* balancer where we can send the request. Thus notice that we have
* changed the route to the backend.
*/
apr_table_setn(r->subprocess_env, "BALANCER_ROUTE_CHANGED", "1");
}
*worker = runtime;
}
(*worker)->s->busy++;
/* Add balancer/worker info to env. */
apr_table_setn(r->subprocess_env,
"BALANCER_NAME", (*balancer)->name);
apr_table_setn(r->subprocess_env,
"BALANCER_WORKER_NAME", (*worker)->name);
apr_table_setn(r->subprocess_env,
"BALANCER_WORKER_ROUTE", (*worker)->s->route);
/* Rewrite the url from 'balancer://url'
* to the 'worker_scheme://worker_hostname[:worker_port]/url'
* This replaces the balancers fictional name with the
* real hostname of the elected worker.
*/
access_status = rewrite_url(r, *worker, url);
/* Add the session route to request notes if present */
if (route) {
apr_table_setn(r->notes, "session-sticky", sticky);
apr_table_setn(r->notes, "session-route", route);
/* Add session info to env. */
apr_table_setn(r->subprocess_env,
"BALANCER_SESSION_STICKY", sticky);
apr_table_setn(r->subprocess_env,
"BALANCER_SESSION_ROUTE", route);
}
ap_log_error(APLOG_MARK, APLOG_DEBUG, 0, r->server,
"proxy: BALANCER (%s) worker (%s) rewritten to %s",
(*balancer)->name, (*worker)->name, *url);
return access_status;
}
/* Find the worker that has the 'route' defined
*/
static proxy_worker *find_route_worker(proxy_balancer *balancer,
const char *route, request_rec *r)
{
int i;
int checking_standby;
int checked_standby;
proxy_worker *worker;
checking_standby = checked_standby = 0;
while (!checked_standby) {
worker = (proxy_worker *)balancer->workers->elts;
for (i = 0; i < balancer->workers->nelts; i++, worker++) {
if ( (checking_standby ? !PROXY_WORKER_IS_STANDBY(worker) : PROXY_WORKER_IS_STANDBY(worker)) )
continue;
if (*(worker->s->route) && strcmp(worker->s->route, route) == 0) {
if (worker && PROXY_WORKER_IS_USABLE(worker)) {
return worker;
} else {
/*
* If the worker is in error state run
* retry on that worker. It will be marked as
* operational if the retry timeout is elapsed.
* The worker might still be unusable, but we try
* anyway.
*/
ap_proxy_retry_worker("BALANCER", worker, r->server);
if (PROXY_WORKER_IS_USABLE(worker)) {
return worker;
} else {
/*
* We have a worker that is unusable.
* It can be in error or disabled, but in case
* it has a redirection set use that redirection worker.
* This enables to safely remove the member from the
* balancer. Of course you will need some kind of
* session replication between those two remote.
*/
if (*worker->s->redirect) {
proxy_worker *rworker = NULL;
rworker = find_route_worker(balancer, worker->s->redirect, r);
/* Check if the redirect worker is usable */
if (rworker && !PROXY_WORKER_IS_USABLE(rworker)) {
/*
* If the worker is in error state run
* retry on that worker. It will be marked as
* operational if the retry timeout is elapsed.
* The worker might still be unusable, but we try
* anyway.
*/
ap_proxy_retry_worker("BALANCER", rworker, r->server);
}
if (rworker && PROXY_WORKER_IS_USABLE(rworker))
return rworker;
}
}
}
}
}
checked_standby = checking_standby++;
}
return NULL;
}