Sessiond rotation thread
authorJulien Desfossez <jdesfossez@efficios.com>
Thu, 14 Dec 2017 21:27:49 +0000 (16:27 -0500)
committerJérémie Galarneau <jeremie.galarneau@efficios.com>
Thu, 15 Mar 2018 15:36:35 +0000 (11:36 -0400)
This thread is responsible to receive the notifications from the
consumers that a channel has finished its rotation and perform the
rename of the chunk ready to be processed by the client when all the
channels of a session have completed their rotation.

Signed-off-by: Julien Desfossez <jdesfossez@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>
include/Makefile.am
include/lttng/rotation.h [new file with mode: 0644]
src/bin/lttng-sessiond/Makefile.am
src/bin/lttng-sessiond/health-sessiond.h
src/bin/lttng-sessiond/main.c
src/bin/lttng-sessiond/rotate.c [new file with mode: 0644]
src/bin/lttng-sessiond/rotate.h [new file with mode: 0644]
src/bin/lttng-sessiond/rotation-thread.c [new file with mode: 0644]
src/bin/lttng-sessiond/rotation-thread.h [new file with mode: 0644]
src/bin/lttng-sessiond/session.h
src/lib/lttng-ctl/lttng-ctl-health.c

index 7de634b8e8a9046d2ed6992de8a6a30e5bd31257..ae9264eab3783df3c6409b42faac3343ef7a1db4 100644 (file)
@@ -78,6 +78,7 @@ lttnginclude_HEADERS = \
        lttng/save.h \
        lttng/load.h \
        lttng/endpoint.h \
+       lttng/rotation.h \
        version.h.tmpl
 
 lttngactioninclude_HEADERS= \
diff --git a/include/lttng/rotation.h b/include/lttng/rotation.h
new file mode 100644 (file)
index 0000000..47ca257
--- /dev/null
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2017 - Julien Desfossez <jdesfossez@efficios.com>
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License, version 2.1 only,
+ * as published by the Free Software Foundation.
+ *
+ * This library is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef LTTNG_ROTATION_H
+#define LTTNG_ROTATION_H
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Return codes for lttng_rotate_session_get_output_path.
+ */
+enum lttng_rotation_status {
+       /*
+        * After starting a rotation.
+        */
+       LTTNG_ROTATION_STATUS_STARTED = 0,
+       /*
+        * When the rotation is complete.
+        */
+       LTTNG_ROTATION_STATUS_COMPLETED = 1,
+       /*
+        * If the handle does not match the last rotate command, we cannot
+        * retrieve the path for the chunk.
+        */
+       LTTNG_ROTATION_STATUS_EXPIRED = 2,
+       /*
+        * On error.
+        */
+       LTTNG_ROTATION_STATUS_ERROR = 3,
+       /*
+        * If no rotation occured during this session.
+        */
+       LTTNG_ROTATION_STATUS_NO_ROTATION = 4,
+};
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* LTTNG_ROTATION_H */
index 413fe75a290bc05940e07f3643ad2b3831fd0527..ea6e9e9bb9770122b8962248d2d055ae74288737 100644 (file)
@@ -35,7 +35,9 @@ lttng_sessiond_SOURCES = utils.c utils.h \
                        notification-thread.h notification-thread.c \
                        notification-thread-commands.h notification-thread-commands.c \
                        notification-thread-events.h notification-thread-events.c \
-                       sessiond-config.h sessiond-config.c
+                       sessiond-config.h sessiond-config.c \
+                       rotate.h rotate.c \
+                       rotation-thread.h rotation-thread.c
 
 if HAVE_LIBLTTNG_UST_CTL
 lttng_sessiond_SOURCES += trace-ust.c ust-registry.c ust-app.c \
index 5d94cc639e2e77476dba2502db5b58e222b5491a..abeb4f0cf13e67b8d2593f0d52bc3deb0f0e189d 100644 (file)
@@ -30,6 +30,7 @@ enum health_type_sessiond {
        HEALTH_SESSIOND_TYPE_APP_MANAGE_NOTIFY  = 6,
        HEALTH_SESSIOND_TYPE_APP_REG_DISPATCH   = 7,
        HEALTH_SESSIOND_TYPE_NOTIFICATION       = 8,
+       HEALTH_SESSIOND_TYPE_ROTATION           = 9,
 
        NR_HEALTH_SESSIOND_TYPES,
 };
index 532e345c08ded85521bce34437d911d58e6156ab..b1229e7214828af2fcb260c3983d0e4d7e3cd1be 100644 (file)
@@ -73,6 +73,7 @@
 #include "load-session-thread.h"
 #include "notification-thread.h"
 #include "notification-thread-commands.h"
+#include "rotation-thread.h"
 #include "syscall.h"
 #include "agent.h"
 #include "ht-cleanup.h"
@@ -208,6 +209,7 @@ static pthread_t ht_cleanup_thread;
 static pthread_t agent_reg_thread;
 static pthread_t load_session_thread;
 static pthread_t notification_thread;
+static pthread_t rotation_thread;
 
 /*
  * UST registration command queue. This queue is tied with a futex and uses a N
@@ -288,6 +290,9 @@ struct load_session_thread_data *load_info;
 /* Notification thread handle. */
 struct notification_thread_handle *notification_thread_handle;
 
+/* Rotation thread handle. */
+struct rotation_thread_handle *rotation_thread_handle;
+
 /* Global hash tables */
 struct lttng_ht *agent_apps_ht_by_sock = NULL;
 
@@ -297,7 +302,7 @@ struct lttng_ht *agent_apps_ht_by_sock = NULL;
  * NR_LTTNG_SESSIOND_READY must match the number of calls to
  * sessiond_notify_ready().
  */
-#define NR_LTTNG_SESSIOND_READY                4
+#define NR_LTTNG_SESSIOND_READY                5
 int lttng_sessiond_ready = NR_LTTNG_SESSIOND_READY;
 
 int sessiond_check_thread_quit_pipe(int fd, uint32_t events)
@@ -5476,6 +5481,7 @@ int main(int argc, char **argv)
                        *ust64_channel_monitor_pipe = NULL,
                        *kernel_channel_monitor_pipe = NULL;
        bool notification_thread_running = false;
+       bool rotation_thread_running = false;
        struct lttng_pipe *ust32_channel_rotate_pipe = NULL,
                        *ust64_channel_rotate_pipe = NULL,
                        *kernel_channel_rotate_pipe = NULL;
@@ -5894,6 +5900,31 @@ int main(int argc, char **argv)
        }
        notification_thread_running = true;
 
+       /* rotation_thread_data acquires the pipes' read side. */
+       rotation_thread_handle = rotation_thread_handle_create(
+                       ust32_channel_rotate_pipe,
+                       ust64_channel_rotate_pipe,
+                       kernel_channel_rotate_pipe,
+                       thread_quit_pipe[0]);
+       if (!rotation_thread_handle) {
+               retval = -1;
+               ERR("Failed to create rotation thread shared data");
+               stop_threads();
+               goto exit_rotation;
+       }
+       rotation_thread_running = true;
+
+       /* Create rotation thread. */
+       ret = pthread_create(&rotation_thread, default_pthread_attr(),
+                       thread_rotation, rotation_thread_handle);
+       if (ret) {
+               errno = ret;
+               PERROR("pthread_create rotation");
+               retval = -1;
+               stop_threads();
+               goto exit_rotation;
+       }
+
        /* Create thread to manage the client socket */
        ret = pthread_create(&client_thread, default_pthread_attr(),
                        thread_manage_clients, (void *) NULL);
@@ -6060,6 +6091,7 @@ exit_dispatch:
        }
 
 exit_client:
+exit_rotation:
 exit_notification:
        ret = pthread_join(health_thread, &status);
        if (ret) {
@@ -6109,6 +6141,18 @@ exit_init_data:
                notification_thread_handle_destroy(notification_thread_handle);
        }
 
+       if (rotation_thread_handle) {
+               if (rotation_thread_running) {
+                       ret = pthread_join(rotation_thread, &status);
+                       if (ret) {
+                               errno = ret;
+                               PERROR("pthread_join rotation thread");
+                               retval = -1;
+                       }
+               }
+               rotation_thread_handle_destroy(rotation_thread_handle);
+       }
+
        rcu_thread_offline();
        rcu_unregister_thread();
 
diff --git a/src/bin/lttng-sessiond/rotate.c b/src/bin/lttng-sessiond/rotate.c
new file mode 100644 (file)
index 0000000..05e9bb0
--- /dev/null
@@ -0,0 +1,320 @@
+/*
+ * Copyright (C) 2017 - Julien Desfossez <jdesfossez@efficios.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License, version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#define _LGPL_SOURCE
+#include <lttng/trigger/trigger.h>
+#include <common/error.h>
+#include <common/config/session-config.h>
+#include <common/defaults.h>
+#include <common/utils.h>
+#include <common/futex.h>
+#include <common/align.h>
+#include <common/time.h>
+#include <common/hashtable/utils.h>
+#include <common/kernel-ctl/kernel-ctl.h>
+#include <sys/eventfd.h>
+#include <sys/stat.h>
+#include <time.h>
+#include <signal.h>
+#include <inttypes.h>
+
+#include "session.h"
+#include "rotate.h"
+#include "rotation-thread.h"
+#include "lttng-sessiond.h"
+#include "health-sessiond.h"
+#include "cmd.h"
+#include "utils.h"
+
+#include <urcu.h>
+#include <urcu/list.h>
+#include <urcu/rculfhash.h>
+
+unsigned long hash_channel_key(struct rotation_channel_key *key)
+{
+       return hash_key_u64(&key->key, lttng_ht_seed) ^ hash_key_ulong(
+                       (void *) (unsigned long) key->domain, lttng_ht_seed);
+}
+
+/* The session's lock must be held by the caller. */
+static
+int session_rename_chunk(struct ltt_session *session, char *current_path,
+               char *new_path)
+{
+       int ret;
+       struct consumer_socket *socket;
+       struct consumer_output *output;
+       struct lttng_ht_iter iter;
+       uid_t uid;
+       gid_t gid;
+
+       DBG("Renaming session chunk path of session \"%s\" from %s to %s",
+                       session->name, current_path, new_path);
+
+       /*
+        * Either one of the sessions is enough to find the consumer_output
+        * and uid/gid.
+        */
+       if (session->kernel_session) {
+               output = session->kernel_session->consumer;
+               uid = session->kernel_session->uid;
+               gid = session->kernel_session->gid;
+       } else if (session->ust_session) {
+               output = session->ust_session->consumer;
+               uid = session->ust_session->uid;
+               gid = session->ust_session->gid;
+       } else {
+               assert(0);
+       }
+
+       if (!output || !output->socks) {
+               ERR("No consumer output found for session \"%s\"",
+                               session->name);
+               ret = -1;
+               goto end;
+       }
+
+       rcu_read_lock();
+       /*
+        * We have to iterate to find a socket, but we only need to send the
+        * rename command to one consumer, so we break after the first one.
+        */
+       cds_lfht_for_each_entry(output->socks->ht, &iter.iter, socket, node.node) {
+               pthread_mutex_lock(socket->lock);
+               ret = consumer_rotate_rename(socket, session->id, output,
+                               current_path, new_path, uid, gid);
+               pthread_mutex_unlock(socket->lock);
+               if (ret) {
+                       ret = -1;
+                       goto end_unlock;
+               }
+               break;
+       }
+
+       ret = 0;
+
+end_unlock:
+       rcu_read_unlock();
+end:
+       return ret;
+}
+
+/* The session's lock must be held by the caller. */
+static
+int rename_first_chunk(struct ltt_session *session,
+               struct consumer_output *consumer, char *new_path)
+{
+       int ret;
+       char current_full_path[LTTNG_PATH_MAX], new_full_path[LTTNG_PATH_MAX];
+
+       /* Current domain path: <session>/kernel */
+       if (session->net_handle > 0) {
+               ret = snprintf(current_full_path, sizeof(current_full_path), "%s/%s",
+                               consumer->dst.net.base_dir, consumer->subdir);
+               if (ret < 0 || ret >= sizeof(current_full_path)) {
+                       ERR("Failed to initialize current full path while renaming first rotation chunk of session \"%s\"",
+                                       session->name);
+                       ret = -1;
+                       goto error;
+               }
+       } else {
+               ret = snprintf(current_full_path, sizeof(current_full_path), "%s/%s",
+                               consumer->dst.session_root_path, consumer->subdir);
+               if (ret < 0 || ret >= sizeof(current_full_path)) {
+                       ERR("Failed to initialize current full path while renaming first rotation chunk of session \"%s\"",
+                                       session->name);
+                       ret = -1;
+                       goto error;
+               }
+       }
+       /* New domain path: <session>/<start-date>-<end-date>-<rotate-count>/kernel */
+       ret = snprintf(new_full_path, sizeof(new_full_path), "%s/%s",
+                       new_path, consumer->subdir);
+       if (ret < 0 || ret >= sizeof(new_full_path)) {
+               ERR("Failed to initialize new full path while renaming first rotation chunk of session \"%s\"",
+                               session->name);
+               ret = -1;
+               goto error;
+       }
+       /*
+        * Move the per-domain fcurrenter inside the first rotation
+        * fcurrenter.
+        */
+       ret = session_rename_chunk(session, current_full_path, new_full_path);
+       if (ret < 0) {
+               ret = -LTTNG_ERR_UNK;
+               goto error;
+       }
+
+       ret = 0;
+
+error:
+       return ret;
+}
+
+/*
+ * Rename a chunk folder after a rotation is complete.
+ * session_lock_list and session lock must be held.
+ *
+ * Returns 0 on success, a negative value on error.
+ */
+int rename_complete_chunk(struct ltt_session *session, time_t ts)
+{
+       struct tm *timeinfo;
+       char datetime[16], start_datetime[16];
+       char new_path[LTTNG_PATH_MAX];
+       int ret;
+       size_t strf_ret;
+
+       DBG("Renaming completed chunk for session %s", session->name);
+       timeinfo = localtime(&ts);
+       if (!timeinfo) {
+               ERR("Failed to retrieve local time while renaming completed chunk");
+               ret = -1;
+               goto end;
+       }
+       strf_ret = strftime(datetime, sizeof(datetime), "%Y%m%d-%H%M%S",
+                       timeinfo);
+       if (strf_ret == 0) {
+               ERR("Failed to format timestamp while renaming completed session chunk");
+               ret = -1;
+               goto end;
+       }
+
+       if (session->rotate_count == 1) {
+               char start_time[16];
+
+               timeinfo = localtime(&session->last_chunk_start_ts);
+               if (!timeinfo) {
+                       ERR("Failed to retrieve local time while renaming completed chunk");
+                       ret = -1;
+                       goto end;
+               }
+
+               strf_ret = strftime(start_time, sizeof(start_time),
+                               "%Y%m%d-%H%M%S", timeinfo);
+               if (strf_ret == 0) {
+                       ERR("Failed to format timestamp while renaming completed session chunk");
+                       ret = -1;
+                       goto end;
+               }
+
+               /*
+                * On the first rotation, the current_rotate_path is the
+                * session_root_path, so we need to create the chunk folder
+                * and move the domain-specific folders inside it.
+                */
+               ret = snprintf(new_path, sizeof(new_path), "%s/%s-%s-%" PRIu64,
+                               session->rotation_chunk.current_rotate_path,
+                               start_time,
+                               datetime, session->rotate_count);
+               if (ret < 0 || ret >= sizeof(new_path)) {
+                       ERR("Failed to format new chunk path while renaming session \"%s\"'s first chunk",
+                                       session->name);
+                       ret = -1;
+                       goto end;
+               }
+
+               if (session->kernel_session) {
+                       ret = rename_first_chunk(session,
+                                       session->kernel_session->consumer,
+                                       new_path);
+                       if (ret) {
+                               ERR("Failed to rename kernel session trace folder to %s", new_path);
+                               /*
+                                * This is not a fatal error for the rotation
+                                * thread, we just need to inform the client
+                                * that a problem occurred with the rotation.
+                                * Returning 0, same for the other errors
+                                * below.
+                                */
+                               ret = 0;
+                               goto error;
+                       }
+               }
+               if (session->ust_session) {
+                       ret = rename_first_chunk(session,
+                                       session->ust_session->consumer,
+                                       new_path);
+                       if (ret) {
+                               ERR("Failed to rename userspace session trace folder to %s", new_path);
+                               ret = 0;
+                               goto error;
+                       }
+               }
+       } else {
+               /*
+                * After the first rotation, all the trace data is already in
+                * its own chunk folder, we just need to append the suffix.
+                */
+               /* Recreate the session->rotation_chunk.current_rotate_path */
+               timeinfo = localtime(&session->last_chunk_start_ts);
+               if (!timeinfo) {
+                       ERR("Failed to retrieve local time while renaming completed chunk");
+                       ret = -1;
+                       goto end;
+               }
+               strf_ret = strftime(start_datetime, sizeof(start_datetime), "%Y%m%d-%H%M%S", timeinfo);
+               if (!strf_ret) {
+                       ERR("Failed to format timestamp while renaming completed session chunk");
+                       ret = -1;
+                       goto end;
+               }
+               ret = snprintf(new_path, sizeof(new_path), "%s/%s-%s-%" PRIu64,
+                               session_get_base_path(session),
+                               start_datetime,
+                               datetime, session->rotate_count);
+               if (ret < 0 || ret >= sizeof(new_path)) {
+                       ERR("Failed to format new chunk path while renaming chunk of session \"%s\"",
+                                       session->name);
+                       ret = -1;
+                       goto error;
+               }
+               ret = session_rename_chunk(session,
+                               session->rotation_chunk.current_rotate_path,
+                               new_path);
+               if (ret) {
+                       ERR("Failed to rename session trace folder from %s to %s",
+                                       session->rotation_chunk.current_rotate_path,
+                                       new_path);
+                       ret = 0;
+                       goto error;
+               }
+       }
+
+       /*
+        * Store the path where the readable chunk is. This path is valid
+        * and can be queried by the client with rotate_pending until the next
+        * rotation is started.
+        */
+       ret = lttng_strncpy(session->rotation_chunk.current_rotate_path,
+                       new_path,
+                       sizeof(session->rotation_chunk.current_rotate_path));
+       if (ret) {
+               ERR("Failed the current chunk's path of session \"%s\"",
+                               session->name);
+               ret = -1;
+               goto error;
+       }
+
+       goto end;
+
+error:
+       session->rotation_status = LTTNG_ROTATION_STATUS_ERROR;
+end:
+       return ret;
+}
diff --git a/src/bin/lttng-sessiond/rotate.h b/src/bin/lttng-sessiond/rotate.h
new file mode 100644 (file)
index 0000000..b2f006f
--- /dev/null
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2017 - Julien Desfossez <jdesfossez@efficios.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License, version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef ROTATE_H
+#define ROTATE_H
+
+#include "rotation-thread.h"
+
+/*
+ * Key in channel_pending_rotate_ht to map a channel to a
+ * struct rotation_channel_info.
+ */
+struct rotation_channel_key {
+       uint64_t key;
+       enum lttng_domain_type domain;
+};
+
+/*
+ * Added in channel_pending_rotate_ht everytime we start the rotation of a
+ * channel. The consumer notifies the rotation thread with the channel_key to
+ * inform a rotation is complete, we use that information to lookup the related
+ * session from channel_pending_rotate_ht.
+ */
+struct rotation_channel_info {
+       uint64_t session_id;
+       struct rotation_channel_key channel_key;
+       struct cds_lfht_node rotate_channels_ht_node;
+};
+
+extern struct cds_lfht *channel_pending_rotate_ht;
+
+unsigned long hash_channel_key(struct rotation_channel_key *key);
+
+/* session lock must be held by this function's caller. */
+int rename_complete_chunk(struct ltt_session *session, time_t ts);
+
+#endif /* ROTATE_H */
diff --git a/src/bin/lttng-sessiond/rotation-thread.c b/src/bin/lttng-sessiond/rotation-thread.c
new file mode 100644 (file)
index 0000000..b245f75
--- /dev/null
@@ -0,0 +1,453 @@
+/*
+ * Copyright (C) 2017 - Julien Desfossez <jdesfossez@efficios.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License, version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#define _LGPL_SOURCE
+#include <lttng/trigger/trigger.h>
+#include <common/error.h>
+#include <common/config/session-config.h>
+#include <common/defaults.h>
+#include <common/utils.h>
+#include <common/futex.h>
+#include <common/align.h>
+#include <common/time.h>
+#include <common/hashtable/utils.h>
+#include <sys/eventfd.h>
+#include <sys/stat.h>
+#include <time.h>
+#include <signal.h>
+#include <inttypes.h>
+
+#include <common/kernel-ctl/kernel-ctl.h>
+#include <lttng/notification/channel-internal.h>
+
+#include "rotation-thread.h"
+#include "lttng-sessiond.h"
+#include "health-sessiond.h"
+#include "rotate.h"
+#include "cmd.h"
+#include "session.h"
+
+#include <urcu.h>
+#include <urcu/list.h>
+#include <urcu/rculfhash.h>
+
+/*
+ * Store a struct rotation_channel_info for each channel that is currently
+ * being rotated by the consumer.
+ */
+struct cds_lfht *channel_pending_rotate_ht;
+
+struct rotation_thread_state {
+       struct lttng_poll_event events;
+};
+
+static
+void channel_rotation_info_destroy(struct rotation_channel_info *channel_info)
+{
+       assert(channel_info);
+       free(channel_info);
+}
+
+static
+int match_channel_info(struct cds_lfht_node *node, const void *key)
+{
+       struct rotation_channel_key *channel_key = (struct rotation_channel_key *) key;
+       struct rotation_channel_info *channel_info;
+
+       channel_info = caa_container_of(node, struct rotation_channel_info,
+                       rotate_channels_ht_node);
+
+       return !!((channel_key->key == channel_info->channel_key.key) &&
+                       (channel_key->domain == channel_info->channel_key.domain));
+}
+
+static
+struct rotation_channel_info *lookup_channel_pending(uint64_t key,
+               enum lttng_domain_type domain)
+{
+       struct cds_lfht_iter iter;
+       struct cds_lfht_node *node;
+       struct rotation_channel_info *channel_info = NULL;
+       struct rotation_channel_key channel_key = { .key = key,
+                       .domain = domain };
+
+       cds_lfht_lookup(channel_pending_rotate_ht,
+                       hash_channel_key(&channel_key),
+                       match_channel_info,
+                       &channel_key, &iter);
+       node = cds_lfht_iter_get_node(&iter);
+       if (!node) {
+               goto end;
+       }
+
+       channel_info = caa_container_of(node, struct rotation_channel_info,
+                       rotate_channels_ht_node);
+       cds_lfht_del(channel_pending_rotate_ht, node);
+end:
+       return channel_info;
+}
+
+/*
+ * Destroy the thread data previously created by the init function.
+ */
+void rotation_thread_handle_destroy(
+               struct rotation_thread_handle *handle)
+{
+       int ret;
+
+       if (!handle) {
+               goto end;
+       }
+
+       if (handle->ust32_consumer >= 0) {
+               ret = close(handle->ust32_consumer);
+               if (ret) {
+                       PERROR("close 32-bit consumer channel rotation pipe");
+               }
+       }
+       if (handle->ust64_consumer >= 0) {
+               ret = close(handle->ust64_consumer);
+               if (ret) {
+                       PERROR("close 64-bit consumer channel rotation pipe");
+               }
+       }
+       if (handle->kernel_consumer >= 0) {
+               ret = close(handle->kernel_consumer);
+               if (ret) {
+                       PERROR("close kernel consumer channel rotation pipe");
+               }
+       }
+
+end:
+       free(handle);
+}
+
+struct rotation_thread_handle *rotation_thread_handle_create(
+               struct lttng_pipe *ust32_channel_rotate_pipe,
+               struct lttng_pipe *ust64_channel_rotate_pipe,
+               struct lttng_pipe *kernel_channel_rotate_pipe,
+               int thread_quit_pipe)
+{
+       struct rotation_thread_handle *handle;
+
+       handle = zmalloc(sizeof(*handle));
+       if (!handle) {
+               goto end;
+       }
+
+       if (ust32_channel_rotate_pipe) {
+               handle->ust32_consumer =
+                               lttng_pipe_release_readfd(
+                                       ust32_channel_rotate_pipe);
+               if (handle->ust32_consumer < 0) {
+                       goto error;
+               }
+       } else {
+               handle->ust32_consumer = -1;
+       }
+       if (ust64_channel_rotate_pipe) {
+               handle->ust64_consumer =
+                               lttng_pipe_release_readfd(
+                                       ust64_channel_rotate_pipe);
+               if (handle->ust64_consumer < 0) {
+                       goto error;
+               }
+       } else {
+               handle->ust64_consumer = -1;
+       }
+       if (kernel_channel_rotate_pipe) {
+               handle->kernel_consumer =
+                               lttng_pipe_release_readfd(
+                                       kernel_channel_rotate_pipe);
+               if (handle->kernel_consumer < 0) {
+                       goto error;
+               }
+       } else {
+               handle->kernel_consumer = -1;
+       }
+       handle->thread_quit_pipe = thread_quit_pipe;
+
+end:
+       return handle;
+error:
+       rotation_thread_handle_destroy(handle);
+       return NULL;
+}
+
+static
+int init_poll_set(struct lttng_poll_event *poll_set,
+               struct rotation_thread_handle *handle)
+{
+       int ret;
+
+       /*
+        * Create pollset with size 4:
+        *      - sessiond quit pipe
+        *      - consumerd (32-bit user space) channel rotate pipe,
+        *      - consumerd (64-bit user space) channel rotate pipe,
+        *      - consumerd (kernel) channel rotate pipe,
+        */
+       ret = lttng_poll_create(poll_set, 4, LTTNG_CLOEXEC);
+       if (ret < 0) {
+               goto end;
+       }
+
+       ret = lttng_poll_add(poll_set, handle->thread_quit_pipe,
+                       LPOLLIN | LPOLLERR);
+       if (ret < 0) {
+               ERR("[rotation-thread] Failed to add thread_quit_pipe fd to pollset");
+               goto error;
+       }
+       ret = lttng_poll_add(poll_set, handle->ust32_consumer,
+                       LPOLLIN | LPOLLERR);
+       if (ret < 0) {
+               ERR("[rotation-thread] Failed to add ust-32 channel rotation pipe fd to pollset");
+               goto error;
+       }
+       ret = lttng_poll_add(poll_set, handle->ust64_consumer,
+                       LPOLLIN | LPOLLERR);
+       if (ret < 0) {
+               ERR("[rotation-thread] Failed to add ust-64 channel rotation pipe fd to pollset");
+               goto error;
+       }
+       if (handle->kernel_consumer >= 0) {
+               ret = lttng_poll_add(poll_set, handle->kernel_consumer,
+                               LPOLLIN | LPOLLERR);
+               if (ret < 0) {
+                       ERR("[rotation-thread] Failed to add kernel channel rotation pipe fd to pollset");
+                       goto error;
+               }
+       }
+
+end:
+       return ret;
+error:
+       lttng_poll_clean(poll_set);
+       return ret;
+}
+
+static
+void fini_thread_state(struct rotation_thread_state *state)
+{
+       lttng_poll_clean(&state->events);
+       cds_lfht_destroy(channel_pending_rotate_ht, NULL);
+}
+
+static
+int init_thread_state(struct rotation_thread_handle *handle,
+               struct rotation_thread_state *state)
+{
+       int ret;
+
+       memset(state, 0, sizeof(*state));
+       lttng_poll_init(&state->events);
+
+       ret = init_poll_set(&state->events, handle);
+       if (ret) {
+               ERR("[rotation-thread] Failed to initialize rotation thread poll set");
+               goto end;
+       }
+
+       channel_pending_rotate_ht = cds_lfht_new(DEFAULT_HT_SIZE,
+                       1, 0, CDS_LFHT_AUTO_RESIZE | CDS_LFHT_ACCOUNTING, NULL);
+       if (!channel_pending_rotate_ht) {
+               ERR("[rotation-thread] Failed to create channel pending rotation hash table");
+               ret = -1;
+               goto end;
+       }
+
+end:
+       return ret;
+}
+
+static
+int handle_channel_rotation_pipe(int fd, uint32_t revents,
+               struct rotation_thread_handle *handle,
+               struct rotation_thread_state *state)
+{
+       int ret = 0;
+       enum lttng_domain_type domain;
+       struct rotation_channel_info *channel_info;
+       struct ltt_session *session = NULL;
+       uint64_t key;
+
+       if (fd == handle->ust32_consumer ||
+                       fd == handle->ust64_consumer) {
+               domain = LTTNG_DOMAIN_UST;
+       } else if (fd == handle->kernel_consumer) {
+               domain = LTTNG_DOMAIN_KERNEL;
+       } else {
+               ERR("[rotation-thread] Unknown channel rotation pipe fd %d",
+                               fd);
+               abort();
+       }
+
+       if (revents & (LPOLLERR | LPOLLHUP | LPOLLRDHUP)) {
+               ret = lttng_poll_del(&state->events, fd);
+               if (ret) {
+                       ERR("[rotation-thread] Failed to remove consumer "
+                                       "rotation pipe from poll set");
+               }
+               goto end;
+       }
+
+       do {
+               ret = read(fd, &key, sizeof(key));
+       } while (ret == -1 && errno == EINTR);
+       if (ret != sizeof(key)) {
+               ERR("[rotation-thread] Failed to read from pipe (fd = %i)",
+                               fd);
+               ret = -1;
+               goto end;
+       }
+
+       DBG("[rotation-thread] Received notification for chan %" PRIu64
+                       ", domain %d\n", key, domain);
+
+       channel_info = lookup_channel_pending(key, domain);
+       if (!channel_info) {
+               ERR("[rotation-thread] Failed to find channel_info (key = %"
+                               PRIu64 ")", key);
+               ret = -1;
+               goto end;
+       }
+       rcu_read_lock();
+       session_lock_list();
+       session = session_find_by_id(channel_info->session_id);
+       if (!session) {
+               /*
+                * The session may have been destroyed before we had a chance to
+                * perform this action, return gracefully.
+                */
+               DBG("[rotation-thread] Session %" PRIu64 " not found",
+                               channel_info->session_id);
+               ret = 0;
+               goto end_unlock_session_list;
+       }
+
+       session_lock(session);
+       if (--session->nr_chan_rotate_pending == 0) {
+               time_t now = time(NULL);
+
+               if (now == (time_t) -1) {
+                       session->rotation_status = LTTNG_ROTATION_STATUS_ERROR;
+                       ret = LTTNG_ERR_UNK;
+                       goto end_unlock_session;
+               }
+
+               ret = rename_complete_chunk(session, now);
+               if (ret < 0) {
+                       ERR("Failed to rename completed rotation chunk");
+                       goto end_unlock_session;
+               }
+               session->rotate_pending = false;
+               session->rotation_status = LTTNG_ROTATION_STATUS_COMPLETED;
+               session->last_chunk_start_ts = session->current_chunk_start_ts;
+               DBG("Rotation completed for session %s", session->name);
+       }
+
+       ret = 0;
+
+end_unlock_session:
+       channel_rotation_info_destroy(channel_info);
+       session_unlock(session);
+end_unlock_session_list:
+       session_unlock_list();
+       rcu_read_unlock();
+end:
+       return ret;
+}
+
+void *thread_rotation(void *data)
+{
+       int ret;
+       struct rotation_thread_handle *handle = data;
+       struct rotation_thread_state state;
+
+       DBG("[rotation-thread] Started rotation thread");
+
+       if (!handle) {
+               ERR("[rotation-thread] Invalid thread context provided");
+               goto end;
+       }
+
+       rcu_register_thread();
+       rcu_thread_online();
+
+       health_register(health_sessiond, HEALTH_SESSIOND_TYPE_ROTATION);
+       health_code_update();
+
+       ret = init_thread_state(handle, &state);
+       if (ret) {
+               goto end;
+       }
+
+       /* Ready to handle client connections. */
+       sessiond_notify_ready();
+
+       while (true) {
+               int fd_count, i;
+
+               health_poll_entry();
+               DBG("[rotation-thread] Entering poll wait");
+               ret = lttng_poll_wait(&state.events, -1);
+               DBG("[rotation-thread] Poll wait returned (%i)", ret);
+               health_poll_exit();
+               if (ret < 0) {
+                       /*
+                        * Restart interrupted system call.
+                        */
+                       if (errno == EINTR) {
+                               continue;
+                       }
+                       ERR("[rotation-thread] Error encountered during lttng_poll_wait (%i)", ret);
+                       goto error;
+               }
+
+               fd_count = ret;
+               for (i = 0; i < fd_count; i++) {
+                       int fd = LTTNG_POLL_GETFD(&state.events, i);
+                       uint32_t revents = LTTNG_POLL_GETEV(&state.events, i);
+
+                       DBG("[rotation-thread] Handling fd (%i) activity (%u)",
+                                       fd, revents);
+
+                       if (fd == handle->thread_quit_pipe) {
+                               DBG("[rotation-thread] Quit pipe activity");
+                               goto exit;
+                       } else if (fd == handle->ust32_consumer ||
+                                       fd == handle->ust64_consumer ||
+                                       fd == handle->kernel_consumer) {
+                               ret = handle_channel_rotation_pipe(fd,
+                                               revents, handle, &state);
+                               if (ret) {
+                                       ERR("[rotation-thread] Handle channel rotation pipe");
+                                       goto error;
+                               }
+                       }
+               }
+       }
+exit:
+error:
+       DBG("[rotation-thread] Exit");
+       fini_thread_state(&state);
+       health_unregister(health_sessiond);
+       rcu_thread_offline();
+       rcu_unregister_thread();
+end:
+       return NULL;
+}
diff --git a/src/bin/lttng-sessiond/rotation-thread.h b/src/bin/lttng-sessiond/rotation-thread.h
new file mode 100644 (file)
index 0000000..64e1ad9
--- /dev/null
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2017 - Julien Desfossez <jdesfossez@efficios.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License, version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef ROTATION_THREAD_H
+#define ROTATION_THREAD_H
+
+#include <urcu/list.h>
+#include <urcu.h>
+#include <urcu/rculfhash.h>
+#include <lttng/domain.h>
+#include <common/pipe.h>
+#include <common/compat/poll.h>
+#include <common/hashtable/hashtable.h>
+#include <pthread.h>
+#include "session.h"
+
+struct rotation_thread_handle {
+       /*
+        * Read side of pipes used to communicate with the rotation thread.
+        */
+       /* Notification from the consumers */
+       int ust32_consumer;
+       int ust64_consumer;
+       int kernel_consumer;
+       /* quit pipe */
+       int thread_quit_pipe;
+};
+
+struct rotation_thread_handle *rotation_thread_handle_create(
+               struct lttng_pipe *ust32_channel_rotate_pipe,
+               struct lttng_pipe *ust64_channel_rotate_pipe,
+               struct lttng_pipe *kernel_channel_rotate_pipe,
+               int thread_quit_pipe);
+
+void rotation_thread_handle_destroy(
+               struct rotation_thread_handle *handle);
+
+void *thread_rotation(void *data);
+
+#endif /* ROTATION_THREAD_H */
index 77f0bf7b1ee87ac4a7b7cd43c731ca0d63701ac4..3b3380c3f4d8f5ec112baedab274969f59765cee 100644 (file)
@@ -22,6 +22,7 @@
 #include <urcu/list.h>
 
 #include <common/hashtable/hashtable.h>
+#include <lttng/rotation.h>
 
 #include "snapshot.h"
 #include "trace-kernel.h"
@@ -117,6 +118,50 @@ struct ltt_session {
         * Node in ltt_sessions_ht_by_id.
         */
        struct lttng_ht_node_u64 node;
+       /* Number of session rotation for this session. */
+       uint64_t rotate_count;
+       /*
+        * Rotation is pending between the time it starts until the consumer has
+        * finished extracting the data. If the session uses a relay, data related
+        * to a rotation can still be in flight after that, see
+        * rotate_pending_relay.
+        */
+       bool rotate_pending;
+       /* Current status of a rotation. */
+       enum lttng_rotation_status rotation_status;
+       /*
+        * Number of channels waiting for a rotation.
+        * When this number reaches 0, we can handle the rename of the chunk
+        * folder and inform the client that the rotate is finished.
+        */
+       unsigned int nr_chan_rotate_pending;
+       struct {
+               /*
+                * When the rotation is in progress, the temporary path name is
+                * stored here. When the rotation is complete, the final path name
+                * is here and can be queried with the rotate_pending call.
+                */
+               char current_rotate_path[LTTNG_PATH_MAX];
+               /*
+                * The path where the consumer is currently writing after the first
+                * session rotation.
+                */
+               char active_tracing_path[LTTNG_PATH_MAX];
+       } rotation_chunk;
+       /*
+        * The timestamp of the beginning of the previous chunk. For the
+        * first chunk, this is the "lttng start" timestamp. For the
+        * subsequent ones, this copies the current_chunk_start_ts value when
+        * a new rotation starts. This value is used to set the name of a
+        * complete chunk directory, ex: "last_chunk_start_ts-now()".
+        */
+       time_t last_chunk_start_ts;
+       /*
+        * This is the timestamp when a new chunk starts. When a new rotation
+        * starts, we copy this value to last_chunk_start_ts and replace it
+        * with the current timestamp.
+        */
+       time_t current_chunk_start_ts;
 };
 
 /* Prototypes */
index fffdfa0d8ecbdee4cef8965a217ca94f19944821..1f1f160563c8212d7d0bcda845bd908a7d3fa45a 100644 (file)
@@ -70,6 +70,7 @@ const char *sessiond_thread_name[NR_HEALTH_SESSIOND_TYPES] = {
        [ HEALTH_SESSIOND_TYPE_HT_CLEANUP ] = "Session daemon hash table cleanup",
        [ HEALTH_SESSIOND_TYPE_APP_MANAGE_NOTIFY ] = "Session daemon application notification manager",
        [ HEALTH_SESSIOND_TYPE_APP_REG_DISPATCH ] = "Session daemon application registration dispatcher",
+       [ HEALTH_SESSIOND_TYPE_ROTATION ] = "Session daemon rotation manager",
 };
 
 static
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