-- keyword -------------------------- defaults - frontend - listen -- backend -
reqtarpit - X X X
retries X - X X
+retry-on X - X X
rspadd - X X X
rspdel - X X X
rspdeny - X X X
See also : "option redispatch"
+retry-on [list of keywords]
+ Specify when to attempt to automatically retry a failed request
+ May be used in sections: defaults | frontend | listen | backend
+ yes | no | yes | yes
+ Arguments :
+ <keywords> is a list of keywords or HTTP status codes, each representing a
+ type of failure event on which an attempt to retry the request
+ is desired. Please read the notes at the bottom before changing
+ this setting. The following keywords are supported :
+
+ none never retry
+
+ conn-failure retry when the connection or the SSL handshake failed
+ and the request could not be sent. This is the default.
+
+ empty-response retry when the server connection was closed after part
+ of the request was sent, and nothing was received from
+ the server. This type of failure may be caused by the
+ request timeout on the server side, poor network
+ condition, or a server crash or restart while
+ processing the request.
+
+ response-timeout the server timeout stroke while waiting for the server
+ to respond to the request. This may be caused by poor
+ network condition, the reuse of an idle connection
+ which has expired on the path, or by the request being
+ extremely expensive to process. It generally is a bad
+ idea to retry on such events on servers dealing with
+ heavy database processing (full scans, etc) as it may
+ amplify denial of service attacks.
+
+ <status> any HTTP status code among "404" (Not Found), "408"
+ (Request Timeout), "425" (Too Early), "500" (Server
+ Error), "501" (Not Implemented), "502" (Bad Gateway),
+ "503" (Service Unavailable), "504" (Gateway Timeout).
+
+ Using this directive replaces any previous settings with the new ones; it is
+ not cumulative.
+
+ Please note that using anything other than "none" and "conn-failure" requires
+ to allocate a buffer and copy the whole request into it, so it has memory and
+ performance impacts. Requests not fitting in a single buffer will never be
+ retried (see the global tune.bufsize setting).
+
+ You have to make sure the application has a replay protection mechanism built
+ in such as a unique transaction IDs passed in requests, or that replaying the
+ same request has no consequence, or it is very dangerous to use any retry-on
+ value beside "conn-failure" and "none". Static file servers and caches are
+ generally considered safe against any type of retry. Using a status code can
+ be useful to quickly leave a server showing an abnormal behavior (out of
+ memory, file system issues, etc), but in this case it may be a good idea to
+ immediately redispatch the connection to another server (please see "option
+ redispatch" for this). Last, it is important to understand that most causes
+ of failures are the requests themselves and that retrying a request causing a
+ server to misbehave will often make the situation even worse for this server,
+ or for the whole service in case of redispatch.
+
+ Unless you know exactly how the application deals with replayed requests, you
+ should not use this directive.
+
+ The default is "conn-failure".
+
+ See also: "retries", "option redispatch", "tune.bufsize"
+
rspadd <string> [{if | unless} <cond>]
Add a header at the end of the HTTP response
May be used in sections : defaults | frontend | listen | backend
Then, to finish, there are 2 informational callbacks:
* 'flt_ops.http_reset': This callback is called when a HTTP message is
- reset. This only happens when a '100-continue' response is received. It
+ reset. This happens either when a '100-continue' response is received, or
+ if we're retrying to send the request to the server after it failed. It
could be useful to reset the filter context before receiving the true
response.
+ You can know why the callback is called by checking s->txn->status. If it's
+ 10X, we're called because of a '100-continue', if not, it's a L7 retry.
* 'flt_ops.http_reply': This callback is called when, at any time, HAProxy
decides to stop the processing on a HTTP message and to send an internal
update_freq_ctr(&fe->fe_req_per_sec, 1));
}
+/* Returns non-zero if the proxy is configured to retry a request if we got that status, 0 overwise */
+static inline int l7_status_match(struct proxy *p, int status)
+{
+ /* Just return 0 if no retry was configured for any status */
+ if (!(p->retry_type & PR_RE_STATUS_MASK))
+ return 0;
+
+ switch (status) {
+ case 404:
+ return (p->retry_type & PR_RE_404);
+ case 408:
+ return (p->retry_type & PR_RE_408);
+ case 425:
+ return (p->retry_type & PR_RE_425);
+ case 500:
+ return (p->retry_type & PR_RE_500);
+ case 501:
+ return (p->retry_type & PR_RE_501);
+ case 502:
+ return (p->retry_type & PR_RE_502);
+ case 503:
+ return (p->retry_type & PR_RE_503);
+ case 504:
+ return (p->retry_type & PR_RE_504);
+ default:
+ break;
+ }
+ return 0;
+}
#endif /* _PROTO_PROXY_H */
/*
* it needs to wait for some reason, any other value
* otherwise.
* - http_reset : Called when the HTTP message is reseted. It happens
- * when a 100-continue response is received.
+ * either when a 100-continue response is received.
+ * that can be detected if s->txn->status is 10X, or
+ * if we're attempting a L7 retry.
* Returns nothing.
* - http_reply : Called when, at any time, HA proxy decides to stop
* the HTTP message's processing and to send a message
#define PR_O2_FAKE_KA 0x00200000 /* pretend we do keep-alive with server eventhough we close */
#define PR_O2_USE_HTX 0x00400000 /* use the HTX representation for the HTTP protocol */
+
#define PR_O2_EXP_NONE 0x00000000 /* http-check : no expect rule */
#define PR_O2_EXP_STS 0x00800000 /* http-check expect status */
#define PR_O2_EXP_RSTS 0x01000000 /* http-check expect rstatus */
#define PR_FBM_MISMATCH_NAME 0x02
#define PR_FBM_MISMATCH_PROXYTYPE 0x04
+/* Bits for the different retry causes */
+#define PR_RE_CONN_FAILED 0x00000001 /* Retry if we failed to connect */
+#define PR_RE_DISCONNECTED 0x00000002 /* Retry if we got disconnected with no answer */
+#define PR_RE_TIMEOUT 0x00000004 /* Retry if we got a server timeout before we got any data */
+#define PR_RE_404 0x00000008 /* Retry if we got a 404 */
+#define PR_RE_408 0x00000010 /* Retry if we got a 408 */
+#define PR_RE_425 0x00000020 /* Retry if we got a 425 */
+#define PR_RE_500 0x00000040 /* Retry if we got a 500 */
+#define PR_RE_501 0x00000080 /* Retry if we got a 501 */
+#define PR_RE_502 0x00000100 /* Retry if we got a 502 */
+#define PR_RE_503 0x00000200 /* Retry if we got a 503 */
+#define PR_RE_504 0x00000400 /* Retry if we got a 504 */
+#define PR_RE_STATUS_MASK (PR_RE_404 | PR_RE_408 | PR_RE_425 | \
+ PR_RE_425 | PR_RE_500 | PR_RE_501 | \
+ PR_RE_502 | PR_RE_503 | PR_RE_504)
struct stream;
struct http_snapshot {
char *server_id_hdr_name; /* the header to use to send the server id (name) */
int server_id_hdr_len; /* the length of the id (name) header... name */
int conn_retries; /* maximum number of connect retries */
+ unsigned int retry_type; /* Type of retry allowed */
int redispatch_after; /* number of retries before redispatch */
unsigned down_trans; /* up-down transitions */
unsigned down_time; /* total time the proxy was down */
SI_FL_RXBLK_CONN = 0x00100000, /* other side is not connected */
SI_FL_RXBLK_ANY = 0x001F0000, /* any of the RXBLK flags above */
SI_FL_RX_WAIT_EP = 0x00200000, /* stream-int waits for more data from the end point */
+ SI_FL_L7_RETRY = 0x01000000, /* The stream interface may attempt L7 retries */
};
/* A stream interface has 3 parts :
int conn_retries; /* number of connect retries left */
unsigned int hcto; /* half-closed timeout (0 = unset) */
struct wait_event wait_event; /* We're in a wait list */
+ struct buffer l7_buffer; /* To store the data, in case we have to retry */
};
/* operations available on a stream-interface */
curproxy->except_mask = defproxy.except_mask;
curproxy->except_to = defproxy.except_to;
curproxy->except_mask_to = defproxy.except_mask_to;
+ curproxy->retry_type = defproxy.retry_type;
if (defproxy.fwdfor_hdr_len) {
curproxy->fwdfor_hdr_len = defproxy.fwdfor_hdr_len;
}
}
+ if ((curproxy->retry_type &~ PR_RE_CONN_FAILED) &&
+ !(curproxy->options2 & PR_O2_USE_HTX)) {
+ ha_warning("Proxy '%s' : retry-on with any other keywords than 'conn-failure' will be ignored, requires 'option http-use-htx'.\n", curproxy->id);
+ err_code |= ERR_WARN;
+ curproxy->retry_type &= PR_RE_CONN_FAILED;
+ }
if (curproxy->email_alert.set) {
if (!(curproxy->email_alert.mailers.name && curproxy->email_alert.from && curproxy->email_alert.to)) {
ha_warning("config : 'email-alert' will be ignored for %s '%s' (the presence any of "
return 0;
}
+/* Reset the stream and the backend stream_interface to a situation suitable for attemption connection */
+/* Returns 0 if we can attempt to retry, -1 otherwise */
+static __inline int do_l7_retry(struct stream *s, struct stream_interface *si)
+{
+ struct channel *req, *res;
+ int co_data;
+
+ si->conn_retries--;
+ if (si->conn_retries < 0)
+ return -1;
+
+ req = &s->req;
+ res = &s->res;
+ /* Remove any write error from the request, and read error from the response */
+ req->flags &= ~(CF_WRITE_ERROR | CF_WRITE_TIMEOUT | CF_SHUTW | CF_SHUTW_NOW);
+ res->flags &= ~(CF_READ_ERROR | CF_READ_TIMEOUT | CF_SHUTR | CF_EOI | CF_READ_NULL | CF_SHUTR_NOW);
+ res->analysers = 0;
+ si->flags &= ~(SI_FL_ERR | SI_FL_EXP | SI_FL_RXBLK_SHUT);
+ si->state = SI_ST_REQ;
+ si->exp = TICK_ETERNITY;
+ res->rex = TICK_ETERNITY;
+ res->to_forward = 0;
+ res->analyse_exp = TICK_ETERNITY;
+ res->total = 0;
+ s->flags &= ~(SF_ASSIGNED | SF_ADDR_SET | SF_ERR_SRVTO | SF_ERR_SRVCL);
+ si_release_endpoint(&s->si[1]);
+ b_free(&req->buf);
+ /* Swap the L7 buffer with the channel buffer */
+ /* We know we stored the co_data as b_data, so get it there */
+ co_data = b_data(&si->l7_buffer);
+ b_set_data(&si->l7_buffer, b_size(&si->l7_buffer));
+ b_xfer(&req->buf, &si->l7_buffer, b_data(&si->l7_buffer));
+
+ co_set_data(req, co_data);
+ b_reset(&res->buf);
+ co_set_data(res, 0);
+ return 0;
+}
+
/* This stream analyser waits for a complete HTTP response. It returns 1 if the
* processing can continue on next analysers, or zero if it either needs more
* data or wants to immediately abort the response (eg: timeout, error, ...). It
struct http_txn *txn = s->txn;
struct http_msg *msg = &txn->rsp;
struct htx *htx;
+ struct stream_interface *si_b = &s->si[1];
struct connection *srv_conn;
struct htx_sl *sl;
int n;
if (txn->flags & TX_NOT_FIRST)
goto abort_keep_alive;
+ if (si_b->flags & SI_FL_L7_RETRY) {
+ /* If we arrive here, then CF_READ_ERROR was
+ * set by si_cs_recv() because we matched a
+ * status, overwise it would have removed
+ * the SI_FL_L7_RETRY flag, so it's ok not
+ * to check s->be->retry_type.
+ */
+ if (co_data(rep) || do_l7_retry(s, si_b) == 0)
+ return 0;
+ }
+
_HA_ATOMIC_ADD(&s->be->be_counters.failed_resp, 1);
if (objt_server(s->target)) {
_HA_ATOMIC_ADD(&__objt_server(s->target)->counters.failed_resp, 1);
/* 2: read timeout : return a 504 to the client. */
else if (rep->flags & CF_READ_TIMEOUT) {
+ if ((si_b->flags & SI_FL_L7_RETRY) &&
+ (s->be->retry_type & PR_RE_TIMEOUT)) {
+ if (co_data(rep) || do_l7_retry(s, si_b) == 0)
+ return 0;
+ }
_HA_ATOMIC_ADD(&s->be->be_counters.failed_resp, 1);
if (objt_server(s->target)) {
_HA_ATOMIC_ADD(&__objt_server(s->target)->counters.failed_resp, 1);
if (txn->flags & TX_NOT_FIRST)
goto abort_keep_alive;
+ if ((si_b->flags & SI_FL_L7_RETRY) &&
+ (s->be->retry_type & PR_RE_DISCONNECTED)) {
+ if (co_data(rep) || do_l7_retry(s, si_b) == 0)
+ return 0;
+ }
+
_HA_ATOMIC_ADD(&s->be->be_counters.failed_resp, 1);
if (objt_server(s->target)) {
_HA_ATOMIC_ADD(&__objt_server(s->target)->counters.failed_resp, 1);
}
}
+/* This function parses a "retry-on" statement */
+static int
+proxy_parse_retry_on(char **args, int section, struct proxy *curpx,
+ struct proxy *defpx, const char *file, int line,
+ char **err)
+{
+ int i;
+
+ if (!(*args[1])) {
+ memprintf(err, "'%s' needs at least one keyword to specify when to retry", args[0]);
+ return -1;
+ }
+ if (!(curpx->cap & PR_CAP_BE)) {
+ memprintf(err, "'%s' only available in backend or listen section", args[0]);
+ return -1;
+ }
+ curpx->retry_type = 0;
+ for (i = 1; *(args[i]); i++) {
+ if (!strcmp(args[i], "conn-failure"))
+ curpx->retry_type |= PR_RE_CONN_FAILED;
+ else if (!strcmp(args[i], "empty-response"))
+ curpx->retry_type |= PR_RE_DISCONNECTED;
+ else if (!strcmp(args[i], "response-timeout"))
+ curpx->retry_type |= PR_RE_TIMEOUT;
+ else if (!strcmp(args[i], "404"))
+ curpx->retry_type |= PR_RE_404;
+ else if (!strcmp(args[i], "408"))
+ curpx->retry_type |= PR_RE_408;
+ else if (!strcmp(args[i], "425"))
+ curpx->retry_type |= PR_RE_425;
+ else if (!strcmp(args[i], "500"))
+ curpx->retry_type |= PR_RE_500;
+ else if (!strcmp(args[i], "501"))
+ curpx->retry_type |= PR_RE_501;
+ else if (!strcmp(args[i], "502"))
+ curpx->retry_type |= PR_RE_502;
+ else if (!strcmp(args[i], "503"))
+ curpx->retry_type |= PR_RE_503;
+ else if (!strcmp(args[i], "504"))
+ curpx->retry_type |= PR_RE_504;
+ else if (!strcmp(args[i], "none")) {
+ if (i != 1 || *args[i + 1]) {
+ memprintf(err, "'%s' 'none' keyworld only usable alone", args[0]);
+ return -1;
+ }
+ } else {
+ memprintf(err, "'%s': unknown keyword '%s'", args[0], args[i]);
+ return -1;
+ }
+
+ }
+
+
+ return 0;
+}
+
/* This function inserts proxy <px> into the tree of known proxies. The proxy's
* name is used as the storing key so it must already have been initialized.
*/
/* HTX is the default mode, for HTTP and TCP */
p->options2 |= PR_O2_USE_HTX;
+ /* Default to only allow L4 retries */
+ p->retry_type = PR_RE_CONN_FAILED;
+
HA_SPIN_INIT(&p->lock);
}
{ CFG_LISTEN, "rate-limit", proxy_parse_rate_limit },
{ CFG_LISTEN, "max-keep-alive-queue", proxy_parse_max_ka_queue },
{ CFG_LISTEN, "declare", proxy_parse_declare },
+ { CFG_LISTEN, "retry-on", proxy_parse_retry_on },
{ 0, NULL, NULL },
}};
if (flt_stream_init(s) < 0 || flt_stream_start(s) < 0)
goto out_fail_accept;
+ s->si[1].l7_buffer = BUF_NULL;
/* finish initialization of the accepted file descriptor */
if (appctx)
si_want_get(&s->si[0]);
tasklet_free(s->si[0].wait_event.task);
tasklet_free(s->si[1].wait_event.task);
+ b_free(&s->si[1].l7_buffer);
if (must_free_sess) {
sess->origin = NULL;
session_free(sess);
/* ensure that we have enough retries left */
si->conn_retries--;
- if (si->conn_retries < 0) {
+ if (si->conn_retries < 0 || !(s->be->retry_type & PR_RE_CONN_FAILED)) {
if (!si->err_type) {
si->err_type = SI_ET_CONN_ERR;
}
*/
si_b->state = SI_ST_REQ; /* new connection requested */
si_b->conn_retries = s->be->conn_retries;
+ if (s->be->retry_type &~ PR_RE_CONN_FAILED)
+ si_b->flags |= SI_FL_L7_RETRY;
}
}
else {
#include <proto/applet.h>
#include <proto/channel.h>
#include <proto/connection.h>
+#include <proto/http_htx.h>
#include <proto/mux_pt.h>
#include <proto/pipe.h>
+#include <proto/proxy.h>
#include <proto/stream.h>
#include <proto/stream_interface.h>
#include <proto/task.h>
if (oc->flags & CF_STREAMER)
send_flag |= CO_SFL_STREAMER;
+ if ((si->flags & SI_FL_L7_RETRY) && !b_data(&si->l7_buffer)) {
+ /* If we want to be able to do L7 retries, copy
+ * the data we're about to send, so that we are able
+ * to resend them if needed
+ */
+ /* Try to allocate a buffer if we had none.
+ * If it fails, the next test will just
+ * disable the l7 retries by setting
+ * l7_conn_retries to 0.
+ */
+ if (!(oc->flags & CF_EOI))
+ si->flags &= ~SI_FL_L7_RETRY;
+ else {
+ if (b_is_null(&si->l7_buffer))
+ b_alloc(&si->l7_buffer);
+ if (b_is_null(&si->l7_buffer))
+ si->flags &= ~SI_FL_L7_RETRY;
+ else {
+ memcpy(b_orig(&si->l7_buffer),
+ b_orig(&oc->buf),
+ b_size(&oc->buf));
+ si->l7_buffer.head = co_data(oc);
+ b_add(&si->l7_buffer, co_data(oc));
+ }
+
+ }
+ }
+
ret = cs->conn->mux->snd_buf(cs, &oc->buf, co_data(oc), send_flag);
if (ret > 0) {
did_send = 1;
break;
}
+ if (si->flags & SI_FL_L7_RETRY) {
+ struct htx *htx;
+ struct htx_sl *sl;
+
+ htx = htxbuf(&ic->buf);
+ if (htx) {
+ sl = http_find_stline(htx);
+ if (sl && l7_status_match(si_strm(si)->be,
+ sl->info.res.status)) {
+ /* If we got a status for which we would
+ * like to retry the request, empty
+ * the buffer and pretend there's an
+ * error on the channel.
+ */
+ ic->flags |= CF_READ_ERROR;
+ htx_reset(htx);
+ return 1;
+ }
+ }
+ si->flags &= ~SI_FL_L7_RETRY;
+ }
cur_read += ret;
/* if we're allowed to directly forward data, we must update ->o */
projects / thirdparty / haproxy.git / commitdiff
