fis-gtm/sr_unix/gtmsource.c

/****************************************************************
 *								*
 *	Copyright 2001, 2011 Fidelity Information Services, Inc	*
 *								*
 *	This source code contains the intellectual property	*
 *	of its copyright holder(s), and is made available	*
 *	under a license.  If you do not know the terms of	*
 *	the license, please stop and do not read further.	*
 *								*
 ****************************************************************/

#include "mdef.h"

#include "gtm_inet.h"
#include <sys/mman.h>
#include "gtm_fcntl.h"
#include "gtm_unistd.h"
#include <errno.h>
#include <sys/sem.h>
#include <sys/wait.h>

#include "gdsroot.h"
#include "gdsblk.h"
#include "gtm_facility.h"
#include "fileinfo.h"
#include "gdsbt.h"
#include "gdsfhead.h"
#include "gdskill.h"
#include "gdscc.h"
#include "filestruct.h"
#include "jnl.h"
#include "buddy_list.h"
#include "hashtab_int4.h"
#include "tp.h"
#include "repl_msg.h"
#include "gtmsource.h"
#include "repl_dbg.h"
#include "error.h"
#include "gtm_stdio.h"
#include "gtm_string.h"
#include "cli.h"
#include "iosp.h"
#include "repl_log.h"
#include "repl_errno.h"
#include "gtm_event_log.h"
#include "repl_shutdcode.h"
#include "repl_sem.h"
#include "repl_filter.h"
#include "eintr_wrappers.h"
#include "send_msg.h"
#include "is_proc_alive.h"
#include "gtmmsg.h"
#include "sgtm_putmsg.h"
#include "repl_comm.h"
#include "repl_instance.h"
#include "ftok_sems.h"
#include "gt_timer.h"		/* for LONG_SLEEP macro (hiber_start function prototype) */
#include "init_secshr_addrs.h"
#include "mutex.h"
#include "gtm_zlib.h"
#include "fork_init.h"

GBLDEF	boolean_t		gtmsource_logstats = FALSE, gtmsource_pool2file_transition = FALSE;
GBLDEF	int			gtmsource_filter = NO_FILTER;
GBLDEF	boolean_t		update_disable = FALSE;

GBLREF	gtmsource_options_t	gtmsource_options;
GBLREF	gtmsource_state_t	gtmsource_state;
GBLREF	boolean_t		is_src_server;
GBLREF	jnlpool_addrs		jnlpool;
GBLREF	uint4			process_id;
GBLREF	int			gtmsource_sock_fd;
GBLREF	int			gtmsource_log_fd;
GBLREF	FILE			*gtmsource_log_fp;
GBLREF	int			gtmsource_statslog_fd;
GBLREF	FILE			*gtmsource_statslog_fp;
GBLREF	gd_addr			*gd_header;
GBLREF	void			(*call_on_signal)();
GBLREF	seq_num			gtmsource_save_read_jnl_seqno, seq_num_zero;
GBLREF	gd_region		*gv_cur_region;
GBLREF	sgmnt_addrs		*cs_addrs;
GBLREF	sgmnt_data_ptr_t	cs_data;
GBLREF	repl_msg_ptr_t		gtmsource_msgp;
GBLREF	int			gtmsource_msgbufsiz;
GBLREF	unsigned char		*gtmsource_tcombuff_start;
GBLREF	uchar_ptr_t		repl_filter_buff;
GBLREF	int			repl_filter_bufsiz;
GBLREF	int			gtmsource_srv_count;
GBLREF	boolean_t		primary_side_std_null_coll;
GBLREF	boolean_t		primary_side_trigger_support;
GBLREF	gd_region		*ftok_sem_reg;
GBLREF	boolean_t		holds_sem[NUM_SEM_SETS][NUM_SRC_SEMS];
GBLREF	IN_PARMS		*cli_lex_in_ptr;
GBLREF	uint4			mutex_per_process_init_pid;

error_def(ERR_JNLPOOLSETUP);
error_def(ERR_MUPCLIERR);
error_def(ERR_NOTALLDBOPN);
error_def(ERR_NULLCOLLDIFF);
error_def(ERR_REPLCOMM);
error_def(ERR_REPLINFO);
error_def(ERR_REPLOFFJNLON);
error_def(ERR_TEXT);

int gtmsource()
{
	gd_region		*reg, *region_top;
	sgmnt_addrs		*csa, *repl_csa;
	boolean_t		jnlpool_creator, all_files_open, isalive;
	int			status, log_init_status, waitpid_res, save_errno;
	pid_t			pid, ppid, procgp;
	seq_num			read_jnl_seqno;
	char			print_msg[1024], tmpmsg[1024];
	unix_db_info		*udi;
	gtmsource_local_ptr_t	gtmsource_local;

	memset((uchar_ptr_t)&jnlpool, 0, SIZEOF(jnlpool_addrs));
	call_on_signal = gtmsource_sigstop;
	ESTABLISH_RET(gtmsource_ch, SS_NORMAL);
	if (-1 == gtmsource_get_opt())
		rts_error(VARLSTCNT(1) ERR_MUPCLIERR);
	if (gtmsource_options.shut_down)
	{	/* Wait till shutdown time nears even before going to "jnlpool_init". This is because the latter will return
		 * with the ftok semaphore and access semaphore held and we do not want to be holding those locks (while
		 * waiting for the user specified timeout to expire) as that will affect new GTM processes and/or other
		 * MUPIP REPLIC commands that need these locks for their function.
		 */
		if (0 < gtmsource_options.shutdown_time)
		{
			repl_log(stdout, TRUE, TRUE, "Waiting for %d seconds before signalling shutdown\n",
												gtmsource_options.shutdown_time);
			LONG_SLEEP(gtmsource_options.shutdown_time);
		} else
			repl_log(stdout, TRUE, TRUE, "Signalling shutdown immediate\n");
	} else if (gtmsource_options.start)
	{
		repl_log(stdout, TRUE, TRUE, "Initiating START of source server for secondary instance [%s]\n",
			gtmsource_options.secondary_instname);
	}
	jnlpool_init(GTMSOURCE, gtmsource_options.start, &jnlpool_creator);
	/* jnlpool_creator == TRUE ==> this process created the journal pool
	 * jnlpool_creator == FALSE ==> journal pool already existed and this process simply attached to it.
	 */
	if (gtmsource_options.shut_down)
		gtmsource_exit(gtmsource_shutdown(FALSE, NORMAL_SHUTDOWN) - NORMAL_SHUTDOWN);
	else if (gtmsource_options.activate)
		gtmsource_exit(gtmsource_mode_change(GTMSOURCE_MODE_ACTIVE) - NORMAL_SHUTDOWN);
	else if (gtmsource_options.deactivate)
		gtmsource_exit(gtmsource_mode_change(GTMSOURCE_MODE_PASSIVE) - NORMAL_SHUTDOWN);
	else if (gtmsource_options.checkhealth)
		gtmsource_exit(gtmsource_checkhealth() - NORMAL_SHUTDOWN);
	else if (gtmsource_options.changelog)
		 gtmsource_exit(gtmsource_changelog() - NORMAL_SHUTDOWN);
	else if (gtmsource_options.showbacklog)
		gtmsource_exit(gtmsource_showbacklog() - NORMAL_SHUTDOWN);
	else if (gtmsource_options.stopsourcefilter)
		gtmsource_exit(gtmsource_stopfilter() - NORMAL_SHUTDOWN);
	else if (gtmsource_options.jnlpool)
		gtmsource_exit(gtmsource_jnlpool() - NORMAL_SHUTDOWN);
	else if (gtmsource_options.losttncomplete)
		gtmsource_exit(gtmsource_losttncomplete() - NORMAL_SHUTDOWN);
	else if (gtmsource_options.needrestart)
		gtmsource_exit(gtmsource_needrestart() - NORMAL_SHUTDOWN);
	else if (!gtmsource_options.start)
	{
		assert(CLI_PRESENT == cli_present("STATSLOG"));
		gtmsource_exit(gtmsource_statslog() - NORMAL_SHUTDOWN);
	}
	assert(gtmsource_options.start);
#ifndef REPL_DEBUG_NOBACKGROUND
	/* Set "child_server_running" to FALSE before forking off child. Wait for it to be set to TRUE by the child. */
	gtmsource_local = jnlpool.gtmsource_local;
	gtmsource_local->child_server_running = FALSE;
	DO_FORK(pid);
	if (0 > pid)
	{
		save_errno = REPL_SEM_ERRNO;
		rts_error(VARLSTCNT(7) ERR_JNLPOOLSETUP, 0,
			ERR_TEXT, 2, RTS_ERROR_LITERAL("Could not fork source server"), save_errno);
	} else if (0 < pid)
	{	/* Parent. Wait until child sets "child_server_running" to FALSE. That is an indication that the child
		 * source server has completed its initialization phase and is all set so the parent command can return.
		 */
		while (isalive = is_proc_alive(pid, 0))	/* note : intended assignment */
		{
			if (gtmsource_local->child_server_running)
				break;
			/* To take care of reassignment of PIDs, the while condition should be && with the condition
			 * (PPID of pid == process_id)
			 */
			SHORT_SLEEP(GTMSOURCE_WAIT_FOR_SRV_START);
			WAITPID(pid, &status, WNOHANG, waitpid_res); /* Release defunct child if dead */
		}
		if (isalive)
		{	/* Child process is alive and started with no issues */
			if (0 != (save_errno = rel_sem(SOURCE, JNL_POOL_ACCESS_SEM)))
				rts_error(VARLSTCNT(7) ERR_JNLPOOLSETUP, 0,
					ERR_TEXT, 2, RTS_ERROR_LITERAL("Error in rel_sem"), save_errno);
			ftok_sem_release(jnlpool.jnlpool_dummy_reg, TRUE, TRUE);
		} else
		{	/* Child source server process errored out at startup and is no longer alive.
			 * If we were the one who created the journal pool, let us clean it up.
			 */
			repl_log(stdout, TRUE, TRUE, "Source server startup failed. See source server log file\n");
			if (jnlpool_creator)
				status = gtmsource_shutdown(TRUE, NORMAL_SHUTDOWN);
		}
		/* If the parent is killed (or crashes) between the fork and exit, checkhealth may not detect that startup
		 * is in progress - parent forks and dies, the system will release sem 0 and 1, checkhealth might test the
		 * value of sem 1 before the child grabs sem 1.
		 */
		gtmsource_exit(isalive ? SRV_ALIVE : SRV_ERR);
	}
	/* The parent process (source server startup command) will be holding the ftok semaphore and jnlpool access semaphore
	 * at this point. The variables that indicate this would have been copied over to the child during the fork. This will
	 * make the child think it is actually holding them as well when actually it is not. Reset those variables in the child
	 * to ensure they do not misrepresent the holder of those semaphores.
	 */
	ftok_sem_reg = NULL;
	udi = FILE_INFO(jnlpool.jnlpool_dummy_reg);
	assert(udi->grabbed_ftok_sem);
	udi->grabbed_ftok_sem = FALSE;
	assert(holds_sem[SOURCE][JNL_POOL_ACCESS_SEM]);
	holds_sem[SOURCE][JNL_POOL_ACCESS_SEM] = FALSE;
	assert(!holds_sem[SOURCE][SRC_SERV_COUNT_SEM]);
	/* Start child source server initialization */
	is_src_server = TRUE;
	process_id = getpid();
	/* Reinvoke secshr related initialization with the child's pid */
	INVOKE_INIT_SECSHR_ADDRS;
	/* Initialize mutex socket, memory semaphore etc. before any "grab_lock" is done by this process on the journal pool. */
	assert(!mutex_per_process_init_pid || mutex_per_process_init_pid == process_id);
	if (!mutex_per_process_init_pid)
		mutex_per_process_init();
	ppid = getppid();
	log_init_status = repl_log_init(REPL_GENERAL_LOG, &gtmsource_log_fd, NULL, gtmsource_options.log_file, NULL);
	assert(SS_NORMAL == log_init_status);
	repl_log_fd2fp(&gtmsource_log_fp, gtmsource_log_fd);
	if (-1 == (procgp = setsid()))
		send_msg(VARLSTCNT(7) ERR_JNLPOOLSETUP, 0, ERR_TEXT, 2, RTS_ERROR_LITERAL("Source server error in setsid"), errno);
#endif /* REPL_DEBUG_NOBACKGROUND */
	if (ZLIB_CMPLVL_NONE != gtm_zlib_cmp_level)
		gtm_zlib_init();	/* Open zlib shared library for compression/decompression */
	REPL_DPRINT1("Setting up regions\n");
	gvinit();

	/* We use the same code dse uses to open all regions but we must make sure they are all open before proceeding. */
	all_files_open = region_init(FALSE);
	if (!all_files_open)
	{
		gtm_putmsg(VARLSTCNT(1) ERR_NOTALLDBOPN);
		gtmsource_exit(ABNORMAL_SHUTDOWN);
	}
	/* Determine primary side null subscripts collation order */
	/* Also check whether all regions have same null collation order */
	primary_side_std_null_coll = -1;
	for (reg = gd_header->regions, region_top = gd_header->regions + gd_header->n_regions; reg < region_top; reg++)
	{
		csa = &FILE_INFO(reg)->s_addrs;
		if (primary_side_std_null_coll != csa->hdr->std_null_coll)
		{
			if (-1 == primary_side_std_null_coll)
				primary_side_std_null_coll = csa->hdr->std_null_coll;
			else
			{
				gtm_putmsg(VARLSTCNT(1) ERR_NULLCOLLDIFF);
				gtmsource_exit(ABNORMAL_SHUTDOWN);
			}
		}
		if (!REPL_ALLOWED(csa) && JNL_ALLOWED(csa))
		{
			gtm_putmsg(VARLSTCNT(4) ERR_REPLOFFJNLON, 2, DB_LEN_STR(reg));
			gtmsource_exit(ABNORMAL_SHUTDOWN);
		}
		if (reg->read_only && REPL_ALLOWED(csa->hdr))
		{
			gtm_putmsg(VARLSTCNT(6) ERR_JNLPOOLSETUP, 0, ERR_TEXT, 2,
				   RTS_ERROR_LITERAL("Source Server does not have write permissions to one or "
					             "more database files that are replicated"));
			gtmsource_exit(ABNORMAL_SHUTDOWN);
		}
	}
	primary_side_trigger_support = GTMTRIG_ONLY(TRUE;) NON_GTMTRIG_ONLY(FALSE;)
	/* Initialize source server alive/dead state related fields in "gtmsource_local" before the ftok semaphore is released */
	gtmsource_local->gtmsource_pid = process_id;
	gtmsource_local->gtmsource_state = GTMSOURCE_START;
	if (jnlpool_creator)
	{
		gtmsource_seqno_init();
		if (ROOTPRIMARY_SPECIFIED == gtmsource_options.rootprimary)
		{	/* Created the journal pool as a root primary. Append a triple to the replication instance file.
			 * Invoke the function "gtmsource_rootprimary_init" to do that. This function though requires that
			 * we hold the ftok semaphore as we will be updating the instance file. But we have a tricky
			 * situation in that the parent source server command is holding the ftok semaphore (and that is
			 * to ensure no one else attaches to the journal pool until the initialization is complete). We
			 * therefore fake the variable that indicates we hold the ftok semaphore and invoke the function.
			 * This way we will not fail any asserts that check this variable. This is ok since we know the
			 * parent is holding the ftok semaphore and waiting for us doing nothing else on the instance file.
			 */
#ifndef REPL_DEBUG_NOBACKGROUND
			udi = FILE_INFO(jnlpool.jnlpool_dummy_reg);
			assert(!udi->grabbed_ftok_sem);
			udi->grabbed_ftok_sem = TRUE;
#endif
			gtmsource_rootprimary_init(jnlpool.jnlpool_ctl->jnl_seqno);
#ifndef REPL_DEBUG_NOBACKGROUND
			udi->grabbed_ftok_sem = FALSE;
#endif
		}
	}
#ifndef REPL_DEBUG_NOBACKGROUND
	/* It is necessary for every process that is using the ftok semaphore to increment the counter by 1. This is used
	 * by the last process that shuts down to delete the ftok semaphore when it notices the counter to be 0.
	 * Note that the parent source server startup command would have done an increment of the ftok counter semaphore
	 * for the replication instance file. But the source server process (the child) that comes here would not have done
	 * that. Do that while the parent is still holding on to the ftok semaphore waiting for our okay.
	 */
	if (!ftok_sem_incrcnt(jnlpool.jnlpool_dummy_reg))
		rts_error(VARLSTCNT(1) ERR_JNLPOOLSETUP);
	/* Increment the source server count semaphore */
	status = incr_sem(SOURCE, SRC_SERV_COUNT_SEM);
	save_errno = REPL_SEM_ERRNO;
	if (0 != status)
	{
		rts_error(VARLSTCNT(7) ERR_JNLPOOLSETUP, 0, ERR_TEXT, 2,
			RTS_ERROR_LITERAL("Counter semaphore increment failure in child source server"), save_errno);
	}
#else
	if (0 != (save_errno = rel_sem_immediate(SOURCE, JNL_POOL_ACCESS_SEM)))
		rts_error(VARLSTCNT(7) ERR_JNLPOOLSETUP, 0, ERR_TEXT, 2,
			RTS_ERROR_LITERAL("Error in rel_sem_immediate"), save_errno);
#endif /* REPL_DEBUG_NOBACKGROUND */

	gtmsource_srv_count++;
	gtmsource_local->child_server_running = TRUE;	/* At this point, the parent startup command will stop waiting for child */
	gtm_event_log_init();
	/* Log source server startup command line first */
	SPRINTF(tmpmsg, "%s %s\n", cli_lex_in_ptr->argv[0], cli_lex_in_ptr->in_str);
	repl_log(gtmsource_log_fp, TRUE, TRUE, tmpmsg);

	SPRINTF(tmpmsg, "GTM Replication Source Server with Pid [%d] started for Secondary Instance [%s]",
		process_id, gtmsource_local->secondary_instname);
	sgtm_putmsg(print_msg, VARLSTCNT(4) ERR_REPLINFO, 2, LEN_AND_STR(tmpmsg));
	repl_log(gtmsource_log_fp, TRUE, TRUE, print_msg);
	gtm_event_log(GTM_EVENT_LOG_ARGC, "MUPIP", "REPLINFO", print_msg);
	jnl_setver();
	do
	{	/* If mode is passive, go to sleep. Wakeup every now and
		 * then and check to see if I have to become active */
		gtmsource_state = gtmsource_local->gtmsource_state = GTMSOURCE_START;
		while (gtmsource_local->mode == GTMSOURCE_MODE_PASSIVE
		       		&& gtmsource_local->shutdown == NO_SHUTDOWN)
			SHORT_SLEEP(GTMSOURCE_WAIT_FOR_MODE_CHANGE);
		if (GTMSOURCE_MODE_PASSIVE == gtmsource_local->mode)
		{	/* Shutdown initiated */
			assert(gtmsource_local->shutdown == SHUTDOWN);
			sgtm_putmsg(print_msg, VARLSTCNT(4) ERR_REPLINFO, 2,
				    RTS_ERROR_LITERAL("GTM Replication Source Server Shutdown signalled"));
			repl_log(gtmsource_log_fp, TRUE, TRUE, print_msg);
			gtm_event_log(GTM_EVENT_LOG_ARGC, "MUPIP", "REPLINFO", print_msg);
			break;
		}
		gtmsource_poll_actions(FALSE);
		if (GTMSOURCE_CHANGING_MODE == gtmsource_state)
			continue;
		SPRINTF(tmpmsg,
				  "GTM Replication Source Server now in ACTIVE mode using port %d",
				  gtmsource_local->secondary_port);
		sgtm_putmsg(print_msg, VARLSTCNT(4) ERR_REPLINFO, 2, LEN_AND_STR(tmpmsg));
		repl_log(gtmsource_log_fp, TRUE, TRUE, print_msg);
		gtm_event_log(GTM_EVENT_LOG_ARGC, "MUPIP", "REPLINFO", print_msg);
		if (SS_NORMAL != (status = gtmsource_alloc_tcombuff()))
			rts_error(VARLSTCNT(7) ERR_REPLCOMM, 0, ERR_TEXT, 2,
				  RTS_ERROR_LITERAL("Error allocating initial tcom buffer space. Malloc error"), status);
		gtmsource_filter = NO_FILTER;
		if ('\0' != gtmsource_local->filter_cmd[0])
		{
			if (SS_NORMAL == (status = repl_filter_init(gtmsource_local->filter_cmd)))
				gtmsource_filter |= EXTERNAL_FILTER;
			else
			{
				if (EREPL_FILTERSTART_EXEC == repl_errno)
					gtmsource_exit(ABNORMAL_SHUTDOWN);
			}
		}
		DEBUG_ONLY(repl_csa = &FILE_INFO(jnlpool.jnlpool_dummy_reg)->s_addrs;)
		assert(!repl_csa->hold_onto_crit);	/* so it is ok to invoke "grab_lock" and "rel_lock" unconditionally */
		grab_lock(jnlpool.jnlpool_dummy_reg);
		QWASSIGN(gtmsource_local->read_addr, jnlpool.jnlpool_ctl->write_addr);
		gtmsource_local->read = jnlpool.jnlpool_ctl->write;
		gtmsource_local->read_state = READ_POOL;
		read_jnl_seqno = gtmsource_local->read_jnl_seqno;
		assert(read_jnl_seqno <= jnlpool.jnlpool_ctl->jnl_seqno);
		if (read_jnl_seqno < jnlpool.jnlpool_ctl->jnl_seqno)
		{
			gtmsource_local->read_state = READ_FILE;
			QWASSIGN(gtmsource_save_read_jnl_seqno, jnlpool.jnlpool_ctl->jnl_seqno);
			gtmsource_pool2file_transition = TRUE; /* so that we read the latest gener jnl files */
		}
		rel_lock(jnlpool.jnlpool_dummy_reg);

		gtmsource_process();

		/* gtmsource_process returns only when mode needs to be changed to PASSIVE */
		assert(gtmsource_state == GTMSOURCE_CHANGING_MODE);
		gtmsource_ctl_close();
		gtmsource_free_msgbuff();
		gtmsource_free_tcombuff();
		gtmsource_free_filter_buff();
		gtmsource_stop_heartbeat();
		if (FD_INVALID != gtmsource_sock_fd)
			repl_close(&gtmsource_sock_fd);
		if (gtmsource_filter & EXTERNAL_FILTER)
			repl_stop_filter();
	} while (TRUE);
	gtmsource_end();
	return(SS_NORMAL);
}