Log to a central server.

Several functions to support centralized logging:

 - create a logging thread upon init
 - gf_log submits log messages to the logging thread which
   in turn sends it to the server using the MOP log

 - on the server side, log messages from a client are written
   to the filename <log file name>.client-<transport-identifier>

Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

2 files changed, 397 insertions, 8 deletions

diff --git a/libglusterfs/src/logging.c b/libglusterfs/src/logging.c
index 6f4eb1fb7..d9a32cc51 100644
--- a/libglusterfs/src/logging.c
+++ b/libglusterfs/src/logging.c
@@ -30,8 +30,10 @@
 #include <locale.h>
 #include <string.h>
 #include <stdlib.h>
-#include "logging.h"
 
+#include "xlator.h"
+#include "logging.h"
+#include "defaults.h"
 
 static pthread_mutex_t  logfile_mutex;
 static char            *filename = NULL;
@@ -103,6 +105,298 @@ gf_log_init (const char *file)
 }
 
 
+static int
+dummy_init (xlator_t *xl)
+{
+	return 0;
+}
+
+
+static int
+gf_log_notify (xlator_t *this_xl, int event, void *data, ...)
+{
+	int ret = 0;
+	
+	switch (event) {
+	case GF_EVENT_CHILD_UP:
+		break;
+                
+	case GF_EVENT_CHILD_DOWN:
+		break;
+                
+	default:
+		ret = default_notify (this_xl, event, data);
+		break;
+	}
+	
+	return ret;
+}
+
+
+/*
+ * Get a dummy xlator for the purpose of central logging.
+ * An xlator is needed because a transport cannot exist without
+ * an xlator.
+ */
+
+static xlator_t *
+__get_dummy_xlator (glusterfs_ctx_t *ctx, const char *remote_host,
+                    const char *transport, uint32_t remote_port)
+{
+        volume_opt_list_t *vol_opt = NULL;
+	xlator_t *         trav    = NULL;
+        
+	int ret = 0;
+        
+	xlator_t *      top    = NULL;
+	xlator_t *      trans  = NULL;
+	xlator_list_t * parent = NULL;
+        xlator_list_t * tmp    = NULL;
+
+	top = CALLOC (1, sizeof (*top));
+        if (!top)
+                goto out;
+
+	trans = CALLOC (1, sizeof (*trans));
+        if (!trans)
+                goto out;
+	
+        INIT_LIST_HEAD (&top->volume_options);
+        INIT_LIST_HEAD (&trans->volume_options);
+
+	top->name     = "log-dummy";
+	top->ctx      = ctx;
+	top->next     = trans;
+	top->init     = dummy_init;
+	top->notify   = gf_log_notify;
+	top->children = (void *) CALLOC (1, sizeof (*top->children));
+        
+	if (!top->children)
+                goto out;
+
+	top->children->xlator = trans;
+	
+	trans->name    = "log-transport";
+	trans->ctx     = ctx;
+	trans->prev    = top;
+	trans->init    = dummy_init;
+	trans->notify  = default_notify;
+	trans->options = get_new_dict ();
+	
+	parent = CALLOC (1, sizeof(*parent));
+
+        if (!parent)
+                goto out;
+
+	parent->xlator = top;
+        
+	if (trans->parents == NULL)
+		trans->parents = parent;
+	else {
+		tmp = trans->parents;
+		while (tmp->next)
+			tmp = tmp->next;
+		tmp->next = parent;
+	}
+
+	/* TODO: log on failure to set dict */
+	if (remote_host) {
+                ret = dict_set (trans->options, "remote-host",
+                                str_to_data ((char *)remote_host));
+        }
+
+	if (remote_port)
+		ret = dict_set_uint32 (trans->options, "remote-port", 
+				       remote_port);
+
+	/* 
+         * 'option remote-subvolume <x>' is needed here even though 
+	 * its not used 
+	 */
+	ret = dict_set_static_ptr (trans->options, "remote-subvolume", 
+				   "brick");
+	ret = dict_set_static_ptr (trans->options, "disable-handshake", "on");
+	ret = dict_set_static_ptr (trans->options, "non-blocking-io", "off");
+	
+	if (transport) {
+		char *transport_type = CALLOC (1, strlen (transport) + 10);
+		ERR_ABORT (transport_type);
+		strcpy(transport_type, transport);
+
+		if (strchr (transport_type, ':'))
+			*(strchr (transport_type, ':')) = '\0';
+
+		ret = dict_set_dynstr (trans->options, "transport-type", 
+				       transport_type);
+	}
+	
+	xlator_set_type (trans, "protocol/client");
+
+        trav = top;
+	while (trav) {
+		/* Get the first volume_option */
+                if (!list_empty (&trav->volume_options)) {
+                        list_for_each_entry (vol_opt, 
+                                             &trav->volume_options, list) 
+                                break;
+                        if ((ret = 
+                             validate_xlator_volume_options (trav, 
+                                                             vol_opt->given_opt)) < 0) {
+                                gf_log (trav->name, GF_LOG_ERROR, 
+                                        "validating translator failed");
+                                return NULL;
+                        }
+                }
+		trav = trav->next;
+	}
+
+	if (xlator_tree_init (top) != 0)
+		return NULL;
+
+out:	
+	return top;
+}
+
+
+/*
+ * Initialize logging to a central server.
+ * If successful, log messages will be written both to
+ * the local file and to the remote server.
+ */
+
+static xlator_t * logging_xl = NULL;
+static int __central_log_enabled = 0;
+
+static pthread_t logging_thread;
+
+struct _msg_queue {
+        struct list_head msgs;
+};
+
+static struct _msg_queue msg_queue;
+
+static pthread_cond_t msg_cond;
+static pthread_mutex_t msg_cond_mutex;
+static pthread_mutex_t msg_queue_mutex;
+
+struct _log_msg {
+        const char *msg;
+        struct list_head queue;
+};
+
+
+int32_t
+gf_log_central_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
+                    int32_t op_ret, int32_t op_errno)
+{
+        struct _log_msg *msg = NULL;
+
+        msg = (struct _log_msg *) cookie;
+
+        FREE (msg->msg);
+
+        STACK_DESTROY (frame->root);
+
+        return 0;
+}
+
+
+void *
+logging_thread_loop (void *arg)
+{
+        struct _log_msg *msg;
+
+        call_frame_t *frame = NULL;
+
+        while (1) {
+                pthread_mutex_lock (&msg_cond_mutex);
+                {
+                        pthread_cond_wait (&msg_cond, &msg_cond_mutex);
+
+                        while (!list_empty (&msg_queue.msgs)) {
+                                pthread_mutex_lock (&msg_queue_mutex);
+                                {
+                                        msg = list_entry (msg_queue.msgs.next,
+                                                          struct _log_msg,
+                                                          queue);
+                                
+                                        list_del_init (&msg->queue);
+                                }
+                                pthread_mutex_unlock (&msg_queue_mutex);
+
+                                frame = create_frame (logging_xl, 
+                                                      logging_xl->ctx->pool);
+                                
+                                frame->local = logging_xl->private;
+                                
+                                STACK_WIND_COOKIE (frame, (void *) msg,
+                                                   gf_log_central_cbk,
+                                                   logging_xl->children->xlator,
+                                                   logging_xl->children->xlator->mops->log,
+                                                   msg->msg);
+                        }
+
+                }
+                pthread_mutex_unlock (&msg_cond_mutex);
+        }
+
+        return NULL;
+}
+
+
+int
+gf_log_central_init (glusterfs_ctx_t *ctx, const char *remote_host,
+                     const char *transport, uint32_t remote_port)
+{
+        logging_xl = __get_dummy_xlator (ctx, remote_host, transport, 
+                                         remote_port);
+        
+        if (!logging_xl) {
+                goto out;
+        }
+
+        __central_log_enabled = 1;
+
+        INIT_LIST_HEAD (&msg_queue.msgs);
+
+        pthread_cond_init (&msg_cond, NULL);
+        pthread_mutex_init (&msg_cond_mutex, NULL);
+        pthread_mutex_init (&msg_queue_mutex, NULL);
+
+        pthread_create (&logging_thread, NULL, logging_thread_loop, NULL);
+
+out:
+        return 0;
+}
+
+
+int
+gf_log_central (const char *msg)
+{
+        struct _log_msg *lm = NULL;
+
+        lm = CALLOC (1, sizeof (*lm));
+        
+        if (!lm)
+                goto out;
+
+        INIT_LIST_HEAD (&lm->queue);
+
+        lm->msg = strdup (msg);
+
+        pthread_mutex_lock (&msg_queue_mutex);
+        {
+                list_add_tail (&lm->queue, &msg_queue.msgs);
+        }
+        pthread_mutex_unlock (&msg_queue_mutex);
+                
+        pthread_cond_signal (&msg_cond);
+
+out:
+        return 0;
+}
+
+
 void 
 gf_log_lock (void)
 {
@@ -134,6 +428,10 @@ _gf_log (const char *domain, const char *file, const char *function, int line,
 	time_t       utime = 0;
 	struct tm   *tm = NULL;
 	char         timestr[256];
+
+        char        *str1, *str2, *msg;
+        size_t      len = 0;
+
 	static char *level_strings[] = {"",  /* NONE */
 					"C", /* CRITICAL */
 					"E", /* ERROR */
@@ -190,18 +488,106 @@ log:
 		else
 			basename = file;
 
-                fprintf (logfile, "[%s] %s [%s:%d:%s] %s: ",
-                         timestr, level_strings[level],
-                         basename, line, function,
-                         domain);
-      
-		vfprintf (logfile, fmt, ap);
+                asprintf (&str1, "[%s] %s [%s:%d:%s] %s: ",
+                          timestr, level_strings[level],
+                          basename, line, function,
+                          domain);
+
+                vasprintf (&str2, fmt, ap);
+
 		va_end (ap);
-		fprintf (logfile, "\n");
+
+                len = strlen (str1);
+                msg = malloc (len + strlen (str2) + 1);
+                
+                strcpy (msg, str1);
+                strcpy (msg + len, str2);
+
+		fprintf (logfile, "%s\n", msg);
 		fflush (logfile);
 	}
 	pthread_mutex_unlock (&logfile_mutex);
 
+        if (__central_log_enabled && 
+            ((glusterfs_central_log_flag_get ()) == 0)) {
+                
+                glusterfs_central_log_flag_set ();
+                {
+                        gf_log_central (msg);
+                }
+                glusterfs_central_log_flag_unset ();
+        }
+
+        FREE (str1);
+        FREE (str2);
+
 out:
 	return (0);
 }
+
+
+struct _client_log {
+        char *identifier;
+        FILE *file;
+        struct list_head list;
+};
+
+struct _client_log *client_logs = NULL;
+
+
+static void
+client_log_init (struct _client_log *cl, char *identifier)
+{
+        char *path = NULL;
+
+        cl->identifier = identifier;
+
+        asprintf (&path, "%s.client-%s", filename, identifier);
+        cl->file = fopen (path, "a");
+        FREE (path);
+        
+        INIT_LIST_HEAD (&cl->list);
+}
+
+
+static FILE *
+__logfile_for_client (char *identifier)
+{
+        struct _client_log *client = NULL;
+
+        if (!client_logs) {
+                client = CALLOC (1, sizeof (*client));
+                client_log_init (client, identifier);
+
+                client_logs = client;
+        }
+
+        list_for_each_entry (client, &client_logs->list, list) {
+                if (!strcmp (client->identifier, identifier))
+                        break;
+        }
+
+        if (!client) {
+                client = CALLOC (1, sizeof (*client));
+
+                client_log_init (client, identifier);
+
+                list_add_tail (&client->list, &client_logs->list);
+        }
+
+        return client->file;
+}
+
+
+int
+gf_log_from_client (const char *msg, char *identifier)
+{
+        FILE *client_log = NULL;
+
+        client_log = __logfile_for_client (identifier);
+
+        fprintf (client_log, "%s\n", msg);
+        fflush (client_log);
+
+        return 0;
+}
diff --git a/libglusterfs/src/logging.h b/libglusterfs/src/logging.h
index d2347c02b..45b4618ae 100644
--- a/libglusterfs/src/logging.h
+++ b/libglusterfs/src/logging.h
@@ -106,6 +106,9 @@ int
 _gf_log (const char *domain, const char *file, const char *function,
 	 int32_t line, gf_loglevel_t level, const char *fmt, ...);
 
+int
+gf_log_from_client (const char *msg, char *identifier);
+
 void gf_log_lock (void);
 void gf_log_unlock (void);