feat(env): set maxreaders greater than the number nginx worker proces…

…ses.
Kong · Nov 6, 2024 · 9a4e355 · 9a4e355
1 parent 890b3ca
commit 9a4e355
Showing 1 changed file with 22 additions and 0 deletions.
diff --git a/src/ngx_lua_resty_lmdb_module.c b/src/ngx_lua_resty_lmdb_module.c
@@ -4,6 +4,9 @@
 #define NGX_LUA_RESTY_LMDB_FILE_MODE        0600
 #define NGX_LUA_RESTY_LMDB_DIR_MODE         0700
 
+/* 126 is the default number of max readers in LMDB */
+#define NGX_LUA_RESTY_LMDB_DEFAULT_READERS         126
+#define NGX_LUA_RESTY_LMDB_MAX_READERS_REDUNDANCY  16
 
 #define NGX_LUA_RESTY_LMDB_VALIDATION_KEY  "validation_tag"
 
@@ -222,11 +225,30 @@ ngx_lua_resty_lmdb_open_file(ngx_cycle_t *cycle,
 {
     int                        rc;
     int                        dead;
+    size_t                     readers;
+    ngx_core_conf_t            *ccf;
 
     if (ngx_lua_resty_lmdb_create_env(cycle, lcf, is_master) != NGX_OK) {
         return NGX_ERROR;
     }
 
+    /* Set max readers depending on the number of worker processes */
+    ccf = (ngx_core_conf_t *) ngx_get_conf(cycle->conf_ctx, ngx_core_module);
+    readers = (size_t)ccf->worker_processes;
+    readers = readers > NGX_LUA_RESTY_LMDB_DEFAULT_READERS ?
+              (readers + NGX_LUA_RESTY_LMDB_MAX_READERS_REDUNDANCY)
+              : NGX_LUA_RESTY_LMDB_DEFAULT_READERS;
+    rc = mdb_env_set_maxreaders(lcf->env, readers);
+    if (rc != 0) {
+        ngx_log_error(NGX_LOG_CRIT, cycle->log, 0,
+                      "unable to set max readers for LMDB environment: %s",
+                      mdb_strerror(rc));
+        mdb_env_close(lcf->env);
+        lcf->env = NULL;
+
+        return NGX_ERROR;
+    }
+
     rc = mdb_env_open(lcf->env, (const char *) lcf->env_path->name.data,
                       0, NGX_LUA_RESTY_LMDB_FILE_MODE);