worker mpm: don't take down the whole server for a transient (eef0a2a0) · Commits · CYBER - Cyber Security / TS 103 523 MSP / TLMSP / TLMSP Apache Httpd

CHANGES

+3 −0

Original line number	Diff line number	Diff line
		Changes with Apache 2.0.55

		*) worker mpm: don't take down the whole server for a transient
		thread creation failure. PR 34514 [Greg Ames]

		*) mod_rewrite: use buffered I/O to improve performance with large
		RewriteMap txt: files. [Greg Ames]

STATUS

+0 −7

Original line number	Diff line number	Diff line
		@@ -122,13 +122,6 @@ PATCHES TO BACKPORT FROM TRUNK:
		+1: jorton, trawick
		[yes, I will write a CHANGES entry too]

		*) worker mpm: don't take down the whole server for a transient
		thread creation failure. PR 34514
		http://svn.apache.org/viewcvs.cgi?rev=168182&view=rev
		http://svn.apache.org/viewcvs.cgi?rev=168649&view=rev
		(ignore changes to event MPM, which don't apply to 2.0.x)
		+1: trawick, jorton, gregames

		*) several changes to improve logging of connection-oriented errors, including
		ap_log_cerror() API (needs minor bump in addition to changes below)
		http://cvs.apache.org/viewcvs.cgi/httpd-2.0/server/core.c?r1=1.289&r2=1.291

server/mpm/worker/worker.c

+46 −26

Original line number	Diff line number	Diff line
		@@ -134,6 +134,7 @@ static int resource_shortage = 0;
		static fd_queue_t *worker_queue;
		static fd_queue_info_t *worker_queue_info;
		static int mpm_state = AP_MPMQ_STARTING;
		static int sick_child_detected;

		/* The structure used to pass unique initialization info to each thread */
		typedef struct {
		@@ -872,14 +873,8 @@ static void create_listener_thread(thread_starter *ts)
		if (rv != APR_SUCCESS) {
		ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf,
		"apr_thread_create: unable to create listener thread");
		/* In case system resources are maxxed out, we don't want
		* Apache running away with the CPU trying to fork over and
		* over and over again if we exit.
		* XXX Jeff doesn't see how Apache is going to try to fork again since
		* the exit code is APEXIT_CHILDFATAL
		*/
		apr_sleep(apr_time_from_sec(10));
		clean_child_exit(APEXIT_CHILDFATAL);
		/* let the parent decide how bad this really is */
		clean_child_exit(APEXIT_CHILDSICK);
		}
		apr_os_thread_get(&listener_os_thread, ts->listener);
		}
		@@ -956,11 +951,8 @@ static void * APR_THREAD_FUNC start_threads(apr_thread_t thd, void dummy)
		if (rv != APR_SUCCESS) {
		ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf,
		"apr_thread_create: unable to create worker thread");
		/* In case system resources are maxxed out, we don't want
		Apache running away with the CPU trying to fork over and
		over and over again if we exit. */
		apr_sleep(apr_time_from_sec(10));
		clean_child_exit(APEXIT_CHILDFATAL);
		/* let the parent decide how bad this really is */
		clean_child_exit(APEXIT_CHILDSICK);
		}
		threads_created++;
		}
		@@ -1153,11 +1145,8 @@ static void child_main(int child_num_arg)
		if (rv != APR_SUCCESS) {
		ap_log_error(APLOG_MARK, APLOG_ALERT, rv, ap_server_conf,
		"apr_thread_create: unable to create worker thread");
		/* In case system resources are maxxed out, we don't want
		Apache running away with the CPU trying to fork over and
		over and over again if we exit. */
		apr_sleep(apr_time_from_sec(10));
		clean_child_exit(APEXIT_CHILDFATAL);
		/* let the parent decide how bad this really is */
		clean_child_exit(APEXIT_CHILDSICK);
		}

		mpm_state = AP_MPMQ_RUNNING;
		@@ -1345,6 +1334,7 @@ static void perform_idle_server_maintenance(void)
		int free_slots[MAX_SPAWN_RATE];
		int last_non_dead;
		int total_non_dead;
		int active_thread_count = 0;

		/* initialize the free_list */
		free_length = 0;
		@@ -1382,15 +1372,17 @@ static void perform_idle_server_maintenance(void)
		* So we hopefully won't need to fork more if we count it.
		* This depends on the ordering of SERVER_READY and SERVER_STARTING.
		*/
		if (ps->pid != 0) { /* XXX just set all_dead_threads in outer for
		loop if no pid? not much else matters */
		if (status <= SERVER_READY && status != SERVER_DEAD &&
		!ps->quiescing &&
		ps->generation == ap_my_generation &&
		/* XXX the following shouldn't be necessary if we clean up
		* properly after seg faults, but we're not yet GLA
		*/
		ps->pid != 0) {
		ps->generation == ap_my_generation) {
		++idle_thread_count;
		}
		if (status >= SERVER_READY && status < SERVER_GRACEFUL) {
		++active_thread_count;
		}
		}
		}
		if (any_dead_threads && totally_free_length < idle_spawn_rate
		&& free_length < MAX_SPAWN_RATE
		@@ -1420,6 +1412,28 @@ static void perform_idle_server_maintenance(void)
		++total_non_dead;
		}
		}

		if (sick_child_detected) {
		if (active_thread_count > 0) {
		/* some child processes appear to be working. don't kill the
		* whole server.
		*/
		sick_child_detected = 0;
		}
		else {
		/* looks like a basket case. give up.
		*/
		shutdown_pending = 1;
		child_fatal = 1;
		ap_log_error(APLOG_MARK, APLOG_ALERT, 0,
		ap_server_conf,
		"No active workers found..."
		" Apache is exiting!");
		/* the child already logged the failure details */
		return;
		}
		}

		ap_max_daemons_limit = last_non_dead + 1;

		if (idle_thread_count > max_spare_threads) {
		@@ -1493,6 +1507,12 @@ static void server_main_loop(int remaining_children_to_start)
		child_fatal = 1;
		return;
		}
		else if (processed_status == APEXIT_CHILDSICK) {
		/* tell perform_idle_server_maintenance to check into this
		* on the next timer pop
		*/
		sick_child_detected = 1;
		}
		/* non-fatal death... note that it's gone in the scoreboard. */
		child_slot = find_child_by_pid(&pid);
		if (child_slot >= 0) {