MINOR: cache: report the number of cache lookups and cache hits

The cache lookups and hits is now accounted per frontend and per backend,
and reported on the stats page.

include/types/counters.h

@@ -56,6 +56,8 @@ struct fe_counters {
 			long long comp_rsp;     /* number of compressed responses */
 			unsigned int rps_max;   /* maximum of new HTTP requests second observed */
 			long long rsp[6];       /* http response codes */
+			long long cache_lookups;/* cache lookups */
+			long long cache_hits;   /* cache hits */
 		} http;
 	} p;                                    /* protocol-specific stats */
 };
@@ -105,6 +107,8 @@ struct be_counters {
 			long long comp_rsp;     /* number of compressed responses */
 			unsigned int rps_max;   /* maximum of new HTTP requests second observed */
 			long long rsp[6];       /* http response codes */
+			long long cache_lookups;/* cache lookups */
+			long long cache_hits;   /* cache hits */
 		} http;
 	} p;                                    /* protocol-specific stats */
 };

include/types/stats.h

@@ -394,6 +394,8 @@ enum stat_field {
 	ST_F_WREW,
 	ST_F_CONNECT,
 	ST_F_REUSE,
+	ST_F_CACHE_LOOKUPS,
+	ST_F_CACHE_HITS,
 
 	/* must always be the last one */
 	ST_F_TOTAL_FIELDS

src/cache.c

@@ -1389,6 +1389,11 @@ enum act_return http_action_req_cache_use(struct act_rule *rule, struct proxy *p
 	if (s->txn->flags & TX_CACHE_IGNORE)
 		return ACT_RET_CONT;
 
+	if (px == strm_fe(s))
+		HA_ATOMIC_ADD(&px->fe_counters.p.http.cache_lookups, 1);
+	else
+		HA_ATOMIC_ADD(&px->be_counters.p.http.cache_lookups, 1);
+
 	shctx_lock(shctx_ptr(cache));
 	res = entry_exist(cache, s->txn->cache_hash);
 	if (res) {
@@ -1402,6 +1407,11 @@ enum act_return http_action_req_cache_use(struct act_rule *rule, struct proxy *p
 			appctx->ctx.cache.entry = res;
 			appctx->ctx.cache.next = NULL;
 			appctx->ctx.cache.sent = 0;
+
+			if (px == strm_fe(s))
+				HA_ATOMIC_ADD(&px->fe_counters.p.http.cache_hits, 1);
+			else
+				HA_ATOMIC_ADD(&px->be_counters.p.http.cache_hits, 1);
 			return ACT_RET_CONT;
 		} else {
 			shctx_lock(shctx_ptr(cache));

src/stats.c

@@ -230,6 +230,8 @@ const char *stat_field_names[ST_F_TOTAL_FIELDS] = {
 	[ST_F_WREW]           = "wrew",
 	[ST_F_CONNECT]        = "connect",
 	[ST_F_REUSE]          = "reuse",
+	[ST_F_CACHE_LOOKUPS]  = "cache_lookups",
+	[ST_F_CACHE_HITS]     = "cache_hits",
 };
 
 /* one line of info */
@@ -724,6 +726,8 @@ static int stats_dump_fields_html(struct buffer *out,
 			              "<tr><th>- HTTP 5xx responses:</th><td>%s</td></tr>"
 			              "<tr><th>- other responses:</th><td>%s</td></tr>"
 			              "<tr><th>Intercepted requests:</th><td>%s</td></tr>"
+			              "<tr><th>Cache lookups:</th><td>%s</td></tr>"
+			              "<tr><th>Cache hits:</th><td>%s</td><td>(%d%%)</td></tr>"
 			              "<tr><th>Failed hdr rewrites:</th><td>%s</td></tr>"
 			              "",
 			              U2H(stats[ST_F_REQ_TOT].u.u64),
@@ -737,6 +741,10 @@ static int stats_dump_fields_html(struct buffer *out,
 			              U2H(stats[ST_F_HRSP_5XX].u.u64),
 			              U2H(stats[ST_F_HRSP_OTHER].u.u64),
 			              U2H(stats[ST_F_INTERCEPTED].u.u64),
+			              U2H(stats[ST_F_CACHE_LOOKUPS].u.u64),
+			              U2H(stats[ST_F_CACHE_HITS].u.u64),
+			              stats[ST_F_CACHE_LOOKUPS].u.u64 ?
+			              (int)(100 * stats[ST_F_CACHE_HITS].u.u64 / stats[ST_F_CACHE_LOOKUPS].u.u64) : 0,
 			              U2H(stats[ST_F_WREW].u.u64));
 		}
 
@@ -1198,6 +1206,8 @@ static int stats_dump_fields_html(struct buffer *out,
 			              "<tr><th>- HTTP 4xx responses:</th><td>%s</td></tr>"
 			              "<tr><th>- HTTP 5xx responses:</th><td>%s</td></tr>"
 			              "<tr><th>- other responses:</th><td>%s</td></tr>"
+			              "<tr><th>Cache lookups:</th><td>%s</td></tr>"
+			              "<tr><th>Cache hits:</th><td>%s</td><td>(%d%%)</td></tr>"
 			              "<tr><th>Failed hdr rewrites:</th><td>%s</td></tr>"
 				      "<tr><th colspan=3>Avg over last 1024 success. conn.</th></tr>"
 			              "",
@@ -1215,6 +1225,10 @@ static int stats_dump_fields_html(struct buffer *out,
 			              U2H(stats[ST_F_HRSP_4XX].u.u64),
 			              U2H(stats[ST_F_HRSP_5XX].u.u64),
 			              U2H(stats[ST_F_HRSP_OTHER].u.u64),
+			              U2H(stats[ST_F_CACHE_LOOKUPS].u.u64),
+			              U2H(stats[ST_F_CACHE_HITS].u.u64),
+			              stats[ST_F_CACHE_LOOKUPS].u.u64 ?
+			              (int)(100 * stats[ST_F_CACHE_HITS].u.u64 / stats[ST_F_CACHE_LOOKUPS].u.u64) : 0,
 			              U2H(stats[ST_F_WREW].u.u64));
 		}
 
@@ -1363,6 +1377,8 @@ int stats_fill_fe_stats(struct proxy *px, struct field *stats, int len)
 		stats[ST_F_HRSP_5XX]    = mkf_u64(FN_COUNTER, px->fe_counters.p.http.rsp[5]);
 		stats[ST_F_HRSP_OTHER]  = mkf_u64(FN_COUNTER, px->fe_counters.p.http.rsp[0]);
 		stats[ST_F_INTERCEPTED] = mkf_u64(FN_COUNTER, px->fe_counters.intercepted_req);
+		stats[ST_F_CACHE_LOOKUPS] = mkf_u64(FN_COUNTER, px->fe_counters.p.http.cache_lookups);
+		stats[ST_F_CACHE_HITS]    = mkf_u64(FN_COUNTER, px->fe_counters.p.http.cache_hits);
 	}
 
 	/* requests : req_rate, req_rate_max, req_tot, */
@@ -1839,6 +1855,8 @@ int stats_fill_be_stats(struct proxy *px, int flags, struct field *stats, int le
 		stats[ST_F_HRSP_4XX]    = mkf_u64(FN_COUNTER, px->be_counters.p.http.rsp[4]);
 		stats[ST_F_HRSP_5XX]    = mkf_u64(FN_COUNTER, px->be_counters.p.http.rsp[5]);
 		stats[ST_F_HRSP_OTHER]  = mkf_u64(FN_COUNTER, px->be_counters.p.http.rsp[0]);
+		stats[ST_F_CACHE_LOOKUPS] = mkf_u64(FN_COUNTER, px->be_counters.p.http.cache_lookups);
+		stats[ST_F_CACHE_HITS]    = mkf_u64(FN_COUNTER, px->be_counters.p.http.cache_hits);
 	}
 
 	stats[ST_F_CLI_ABRT]     = mkf_u64(FN_COUNTER, px->be_counters.cli_aborts);