src/tools/csqlserver.cxx

Go to the documentation of this file.

/***************************************************************************
 *   Copyright (C) 2007 by www.databasecache.com                           *
 *   Contact: praba_tuty@databasecache.com                                 *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   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.                          *
 *                                                                         *
  ***************************************************************************/
#include<CSql.h>
#include<SessionImpl.h>
#include<Debug.h>
#include<Process.h>
#include<Database.h>
#include<Transaction.h>
#include<Lock.h>
#include<CacheTableLoader.h>
char* version = "csql-linux-i686-2.0GA";
int srvStop =0;
pid_t replpid=0;
pid_t cachepid=0;
void dumpData();
static void sigTermHandler(int sig)
{
    printf("Received signal %d\nStopping the server\n", sig);
    srvStop = 1;
}

bool checkDead(pid_t  pid)
{
    int ret = os::kill(pid, 0);
    if (ret == -1) return true; else return false;
}

DbRetVal releaseAllResources(Database *sysdb, ThreadInfo *info )
{
    printf("Releasing all the resources for process %d %lu\n", info->pid_, info->thrid_);
    //recover for all the mutexes in has_
    for (int i =0;  i < MAX_MUTEX_PER_THREAD; i++)
    {
        if (info->has_[i] != NULL) 
        {
            printf("Dead Procs: %d %lu holding mutex %x %s \n", info->pid_, info->thrid_, info->has_[i], info->has_[i]->name);
            logFine(logger, "Dead Procs: %d %lu holding mutex %x %s \n", info->pid_, info->thrid_, info->has_[i], info->has_[i]->name);
            //TODO::recovery of mutexes 
            //info->has_[i]->recoverMutex();
            srvStop = 1;
            return ErrSysFatal;
        }
    }
    TransactionManager *tm = new TransactionManager();
    LockManager *lm = new LockManager(sysdb);
    for (int i = 0 ;i < MAX_THREADS_PER_PROCESS; i++)
    {
        if (info->thrTrans_[i].trans_ != NULL && info->thrTrans_[i].trans_->status_ == TransRunning)
        {
            printf("Rollback Transaction %x\n", info->thrTrans_[i].trans_);
            tm->rollback(lm, info->thrTrans_[i].trans_);
        }
    }
    info->init();
    delete tm;
    delete lm;
    return OK;
}

DbRetVal cleanupDeadProcs(Database *sysdb)
{
    DbRetVal rv = sysdb->getProcessTableMutex(false);
    if (OK != rv)
    {
        printError(rv,"Unable to get process table mutex");
        return rv;
    }
    pid_t pid;
    pid = os::getpid();
    pthread_t thrid = os::getthrid();


    ThreadInfo* pInfo = sysdb->getThreadInfo(0);
    int i=0;
    ThreadInfo* freeSlot = NULL;
    for (; i < Conf::config.getMaxProcs(); i++)
    {
        //check whether it is alive
        if (pInfo->pid_ !=0 && checkDead(pInfo->pid_)) releaseAllResources(sysdb, pInfo);
        pInfo++;
    }
    sysdb->releaseProcessTableMutex(false);
    return OK;
}


DbRetVal logActiveProcs(Database *sysdb)
{
    DbRetVal rv = sysdb->getProcessTableMutex(false);
    if (OK != rv)
    {
        printError(rv,"Unable to get process table mutex");
        return rv;
    }
    ThreadInfo* pInfo = sysdb->getThreadInfo(0);
    int i=0;
    ThreadInfo* freeSlot = NULL;
    for (; i < Conf::config.getMaxProcs(); i++)
    {
        if (pInfo->pid_ !=0 )  logFine(logger, "Registered Procs: %d %lu\n", pInfo->pid_, pInfo->thrid_);
        pInfo++;
    }
    sysdb->releaseProcessTableMutex(false);
    return OK;
}
void startCacheServer()
{
     printf("Starting Cache Recv Server\n");
     char execName[1024];
     sprintf(execName, "%s/bin/csqlcacheserver", os::getenv("CSQL_INSTALL_ROOT"));
     printf("filename is %s\n", execName);
     cachepid = os::createProcess(execName, "-s");
     if (cachepid != -1)
         printf("Cache Recv Server Started pid=%d\n", cachepid);
     return;
}

void printUsage()
{
   printf("Usage: csqlserver [-c] [-v]\n");
   printf("       v -> print the version.\n");
   printf("       c -> recover all cached tables from the target database.\n");
   printf("Description: Start the csql server and initialize the database.\n");
   return;
}
int main(int argc, char **argv)
{
    int c = 0, opt = 0;
    while ((c = getopt(argc, argv, "cv?")) != EOF) 
    {
        switch (c)
        {
            case '?' : { opt = 10; break; } //print help 
            case 'c' : { opt = 1; break; } //recover all the tables from cache
            case 'v' : { opt = 2; break; } //print version
            default: opt=10; 

        }
    }//while options

    if (opt == 10) {
        printUsage();
        return 0;
    }else if (opt ==2) {
        printf("%s\n",version);
        return 0;
    }

    SessionImpl session;
    DbRetVal rv = session.readConfigFile();
    if (rv != OK)
    {
        printf("Unable to read the configuration file \n");
        return 1;
    }
    os::signal(SIGINT, sigTermHandler);
    os::signal(SIGTERM, sigTermHandler);
    rv = logger.startLogger(Conf::config.getLogFile(), true);
    if (rv != OK)
    {
        printf("Unable to start the logger\n");
        return 2;
    }

    logFine(logger, "Server Started");
    int ret  = session.initSystemDatabase();
    if (0  != ret)
    {
        printf(" System Database Initialization failed\n");
        return 3;
    }
    printf("System Database initialized\n");


    bool end = false;

    struct timeval timeout, tval;
    timeout.tv_sec = 5;
    timeout.tv_usec = 0;
    Database* sysdb = session.getSystemDatabase();
    if (FILE *file = fopen(Conf::config.getDbFile(), "r"))
    {
        fclose(file);
        char cmd[1024];
        sprintf(cmd, "csql -S -s %s",Conf::config.getDbFile()); 
        int ret = system(cmd);
        if (ret != 0) { 
            printf("Tables cannot be recovered. DB file corrupted\n");
        }
    }
    if (opt == 1) {
        if (Conf::config.useCache()) {
            printf("Database server recovering cached tables...\n");
            int ret = system("cachetable -U root -P manager -R");
            if (ret != 0) { 
                printf("Cached Tables recovery failed %d\n", ret);
                logger.stopLogger();
                session.destroySystemDatabase();
                return 2;
            }
            printf("Cached Tables recovered\n");
        } else {
            printf("Cache mode is not set in csql.conf. Cannot recover\n");
            logger.stopLogger();
            session.destroySystemDatabase();
            return 1;
        }
    }
    if (Conf::config.useReplication())
    {
        printf("Starting Replication Server\n");
        char execName[1024];
        sprintf(execName, "%s/bin/csqlreplserver", os::getenv("CSQL_INSTALL_ROOT"));
        printf("filename is %s\n", execName);
        replpid = os::createProcess(execName, "-s");
        if (replpid != -1) 
            printf("Repl Server Started pid=%d\n", replpid);
        
    }
    if (Conf::config.useCache() && Conf::config.useTwoWayCache()) startCacheServer();

    printf("Database server started\n");

    while(!srvStop)
    {
        tval.tv_sec = timeout.tv_sec;
        tval.tv_usec = timeout.tv_usec;
        os::select(0, 0, 0, 0, &tval);
        
        //send signal to all the registered process..check they are alive
        cleanupDeadProcs(sysdb);

        //TODO::check repl server is alive, if not restart it
        
        //TODO::if it fails to start 5 times, exit
        if (cachepid !=0  && checkDead(cachepid)) startCacheServer();
        
    }
    os::kill(cachepid, SIGTERM);
    dumpData();
    logFine(logger, "Server Exiting");
    logActiveProcs(sysdb);
    printf("Server Exiting\n");
    logFine(logger, "Server Ended");
    logger.stopLogger();
    session.destroySystemDatabase();
    return 0;
}
void dumpData()
{
    char cmd[1024];
    sprintf(cmd, "csqldump >%s",Conf::config.getDbFile()); 
    int ret = system(cmd);
    if (ret != 0) { 
        printf("Table cannot be written. Recovery will fail\n");
    }
    return;
}

---