Adding upstream version 2.4.38.upstream/2.4.38upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 465 insertions, 0 deletions

diff --git a/modules/proxy/balancers/mod_lbmethod_heartbeat.c b/modules/proxy/balancers/mod_lbmethod_heartbeat.c
new file mode 100644
index 0000000..7aeaf71
--- /dev/null
+++ b/modules/proxy/balancers/mod_lbmethod_heartbeat.c
@@ -0,0 +1,465 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "mod_proxy.h"
+#include "scoreboard.h"
+#include "ap_mpm.h"
+#include "apr_version.h"
+#include "ap_hooks.h"
+#include "ap_slotmem.h"
+#include "heartbeat.h"
+
+#ifndef LBM_HEARTBEAT_MAX_LASTSEEN
+/* If we haven't seen a heartbeat in the last N seconds, don't count this IP
+ * as allive.
+ */
+#define LBM_HEARTBEAT_MAX_LASTSEEN (10)
+#endif
+
+module AP_MODULE_DECLARE_DATA lbmethod_heartbeat_module;
+
+static int (*ap_proxy_retry_worker_fn)(const char *proxy_function,
+        proxy_worker *worker, server_rec *s) = NULL;
+
+static const ap_slotmem_provider_t *storage = NULL;
+static ap_slotmem_instance_t *hm_serversmem = NULL;
+
+/*
+ * configuration structure
+ * path: path of the file where the heartbeat information is stored.
+ */
+typedef struct lb_hb_ctx_t
+{
+    const char *path;
+} lb_hb_ctx_t;
+
+typedef struct hb_server_t {
+    const char *ip;
+    int busy;
+    int ready;
+    int port;
+    int id;
+    apr_time_t seen;
+    proxy_worker *worker;
+} hb_server_t;
+
+typedef struct ctx_servers {
+    apr_time_t now;
+    apr_hash_t *servers;
+} ctx_servers_t;
+
+static void
+argstr_to_table(apr_pool_t *p, char *str, apr_table_t *parms)
+{
+    char *key;
+    char *value;
+    char *strtok_state;
+
+    key = apr_strtok(str, "&", &strtok_state);
+    while (key) {
+        value = strchr(key, '=');
+        if (value) {
+            *value = '\0';      /* Split the string in two */
+            value++;            /* Skip passed the = */
+        }
+        else {
+            value = "1";
+        }
+        ap_unescape_url(key);
+        ap_unescape_url(value);
+        apr_table_set(parms, key, value);
+        /*
+         ap_log_rerror(APLOG_MARK, APLOG_DEBUG, 0, r, APLOGNO(03230)
+         "Found query arg: %s = %s", key, value);
+         */
+        key = apr_strtok(NULL, "&", &strtok_state);
+    }
+}
+
+static apr_status_t readfile_heartbeats(const char *path, apr_hash_t *servers,
+                                    apr_pool_t *pool)
+{
+    apr_finfo_t fi;
+    apr_status_t rv;
+    apr_file_t *fp;
+
+    if (!path) {
+        return APR_SUCCESS;
+    }
+
+    rv = apr_file_open(&fp, path, APR_READ|APR_BINARY|APR_BUFFERED,
+                       APR_OS_DEFAULT, pool);
+
+    if (rv) {
+        return rv;
+    }
+
+    rv = apr_file_info_get(&fi, APR_FINFO_SIZE, fp);
+
+    if (rv) {
+        return rv;
+    }
+
+    {
+        char *t;
+        int lineno = 0;
+        apr_bucket_alloc_t *ba = apr_bucket_alloc_create(pool);
+        apr_bucket_brigade *bb = apr_brigade_create(pool, ba);
+        apr_bucket_brigade *tmpbb = apr_brigade_create(pool, ba);
+        apr_table_t *hbt = apr_table_make(pool, 10);
+
+        apr_brigade_insert_file(bb, fp, 0, fi.size, pool);
+
+        do {
+            hb_server_t *server;
+            char buf[4096];
+            apr_size_t bsize = sizeof(buf);
+            const char *ip, *val;
+
+            apr_brigade_cleanup(tmpbb);
+
+            if (APR_BRIGADE_EMPTY(bb)) {
+                break;
+            }
+
+            rv = apr_brigade_split_line(tmpbb, bb,
+                                        APR_BLOCK_READ, sizeof(buf));
+            lineno++;
+
+            if (rv) {
+                return rv;
+            }
+
+            apr_brigade_flatten(tmpbb, buf, &bsize);
+
+            if (bsize == 0) {
+                break;
+            }
+
+            buf[bsize - 1] = 0;
+
+            /* comment */
+            if (buf[0] == '#') {
+                continue;
+            }
+
+            /* line format: <IP> <query_string>\n */
+            t = strchr(buf, ' ');
+            if (!t) {
+                continue;
+            }
+
+            ip = apr_pstrmemdup(pool, buf, t - buf);
+            t++;
+
+            server = apr_hash_get(servers, ip, APR_HASH_KEY_STRING);
+
+            if (server == NULL) {
+                server = apr_pcalloc(pool, sizeof(hb_server_t));
+                server->ip = ip;
+                server->port = 80;
+                server->seen = -1;
+
+                apr_hash_set(servers, server->ip, APR_HASH_KEY_STRING, server);
+            }
+
+            apr_table_clear(hbt);
+
+            argstr_to_table(pool, apr_pstrdup(pool, t), hbt);
+
+            if ((val = apr_table_get(hbt, "busy"))) {
+                server->busy = atoi(val);
+            }
+
+            if ((val = apr_table_get(hbt, "ready"))) {
+                server->ready = atoi(val);
+            }
+
+            if ((val = apr_table_get(hbt, "lastseen"))) {
+                server->seen = atoi(val);
+            }
+
+            if ((val = apr_table_get(hbt, "port"))) {
+                server->port = atoi(val);
+            }
+
+            if (server->busy == 0 && server->ready != 0) {
+                /* Server has zero threads active, but lots of them ready,
+                 * it likely just started up, so lets /4 the number ready,
+                 * to prevent us from completely flooding it with all new
+                 * requests.
+                 */
+                server->ready = server->ready / 4;
+            }
+
+        } while (1);
+    }
+
+    return APR_SUCCESS;
+}
+
+static apr_status_t hm_read(void* mem, void *data, apr_pool_t *pool)
+{
+    hm_slot_server_t *slotserver = (hm_slot_server_t *) mem;
+    ctx_servers_t *ctx = (ctx_servers_t *) data;
+    apr_hash_t *servers = (apr_hash_t *) ctx->servers;
+    hb_server_t *server = apr_hash_get(servers, slotserver->ip, APR_HASH_KEY_STRING);
+    if (server == NULL) {
+        server = apr_pcalloc(pool, sizeof(hb_server_t));
+        server->ip = apr_pstrdup(pool, slotserver->ip);
+        server->seen = -1;
+
+        apr_hash_set(servers, server->ip, APR_HASH_KEY_STRING, server);
+
+    }
+    server->busy = slotserver->busy;
+    server->ready = slotserver->ready;
+    server->seen = apr_time_sec(ctx->now - slotserver->seen);
+    server->id = slotserver->id;
+    if (server->busy == 0 && server->ready != 0) {
+        server->ready = server->ready / 4;
+    }
+    return APR_SUCCESS;
+}
+static apr_status_t readslot_heartbeats(ctx_servers_t *ctx,
+                                    apr_pool_t *pool)
+{
+    storage->doall(hm_serversmem, hm_read, ctx, pool);
+    return APR_SUCCESS;
+}
+
+
+static apr_status_t read_heartbeats(const char *path, apr_hash_t *servers,
+                                        apr_pool_t *pool)
+{
+    apr_status_t rv;
+    if (hm_serversmem) {
+        ctx_servers_t ctx;
+        ctx.now = apr_time_now();
+        ctx.servers = servers;
+        rv = readslot_heartbeats(&ctx, pool);
+    } else
+        rv = readfile_heartbeats(path, servers, pool);
+    return rv;
+}
+
+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);
+
+    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_ex, 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;
+        }
+    }
+
+    apr_pool_destroy(tpool);
+
+    return mycandidate;
+}
+
+static apr_status_t reset(proxy_balancer *balancer, server_rec *s)
+{
+    return APR_SUCCESS;
+}
+
+static apr_status_t age(proxy_balancer *balancer, server_rec *s)
+{
+    return APR_SUCCESS;
+}
+
+static const proxy_balancer_method heartbeat =
+{
+    "heartbeat",
+    &find_best_hb,
+    NULL,
+    &reset,
+    &age,
+    NULL
+};
+
+static int lb_hb_init(apr_pool_t *p, apr_pool_t *plog,
+                      apr_pool_t *ptemp, server_rec *s)
+{
+    apr_size_t size;
+    unsigned int num;
+    lb_hb_ctx_t *ctx = ap_get_module_config(s->module_config,
+                                            &lbmethod_heartbeat_module);
+
+    /* do nothing on first call */
+    if (ap_state_query(AP_SQ_MAIN_STATE) == AP_SQ_MS_CREATE_PRE_CONFIG)
+        return OK;
+
+    storage = ap_lookup_provider(AP_SLOTMEM_PROVIDER_GROUP, "shm",
+                                 AP_SLOTMEM_PROVIDER_VERSION);
+    if (!storage) {
+        ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, s, APLOGNO(02281)
+                     "Failed to lookup provider 'shm' for '%s'. Maybe you "
+                     "need to load mod_slotmem_shm?",
+                     AP_SLOTMEM_PROVIDER_GROUP);
+        return OK;
+    }
+
+    /* Try to use a slotmem created by mod_heartmonitor */
+    storage->attach(&hm_serversmem, "mod_heartmonitor", &size, &num, p);
+    if (!hm_serversmem)
+        ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, s, APLOGNO(02282)
+                     "No slotmem from mod_heartmonitor");
+    else
+        ap_log_error(APLOG_MARK, APLOG_NOTICE, 0, s, APLOGNO(02283)
+                     "Using slotmem from mod_heartmonitor");
+
+    if (hm_serversmem)
+        ctx->path = "(slotmem)";
+
+    return OK;
+}
+
+static void register_hooks(apr_pool_t *p)
+{
+    static const char * const aszPred[]={ "mod_heartmonitor.c", NULL };
+    ap_register_provider(p, PROXY_LBMETHOD, "heartbeat", "0", &heartbeat);
+    ap_hook_post_config(lb_hb_init, aszPred, NULL, APR_HOOK_MIDDLE);
+}
+
+static void *lb_hb_create_config(apr_pool_t *p, server_rec *s)
+{
+    lb_hb_ctx_t *ctx = (lb_hb_ctx_t *) apr_palloc(p, sizeof(lb_hb_ctx_t));
+
+    ctx->path = ap_runtime_dir_relative(p, DEFAULT_HEARTBEAT_STORAGE);
+
+    return ctx;
+}
+
+static void *lb_hb_merge_config(apr_pool_t *p, void *basev, void *overridesv)
+{
+    lb_hb_ctx_t *ps = apr_pcalloc(p, sizeof(lb_hb_ctx_t));
+    lb_hb_ctx_t *base = (lb_hb_ctx_t *) basev;
+    lb_hb_ctx_t *overrides = (lb_hb_ctx_t *) overridesv;
+
+    if (overrides->path) {
+        ps->path = apr_pstrdup(p, overrides->path);
+    }
+    else {
+        ps->path = apr_pstrdup(p, base->path);
+    }
+
+    return ps;
+}
+
+static const char *cmd_lb_hb_storage(cmd_parms *cmd,
+                                  void *dconf, const char *path)
+{
+    apr_pool_t *p = cmd->pool;
+    lb_hb_ctx_t *ctx =
+    (lb_hb_ctx_t *) ap_get_module_config(cmd->server->module_config,
+                                         &lbmethod_heartbeat_module);
+
+    const char *err = ap_check_cmd_context(cmd, GLOBAL_ONLY);
+
+    if (err != NULL) {
+        return err;
+    }
+
+    ctx->path = ap_runtime_dir_relative(p, path);
+
+    return NULL;
+}
+
+static const command_rec cmds[] = {
+    AP_INIT_TAKE1("HeartbeatStorage", cmd_lb_hb_storage, NULL, RSRC_CONF,
+                  "Path to read heartbeat data."),
+    {NULL}
+};
+
+AP_DECLARE_MODULE(lbmethod_heartbeat) = {
+    STANDARD20_MODULE_STUFF,
+    NULL,                       /* create per-directory config structure */
+    NULL,                       /* merge per-directory config structures */
+    lb_hb_create_config,        /* create per-server config structure */
+    lb_hb_merge_config,         /* merge per-server config structures */
+    cmds,                       /* command apr_table_t */
+    register_hooks              /* register hooks */
+};