trunk/tools/ClusterConnection.java

package tools;
import java.sql.*;
import java.util.ArrayList;
import java.util.HashMap;

/**
 * ClusterConnection class to wrap the master/node mysql servers so that is transparent to other programs
 * @author Jose Duarte
 */

public class ClusterConnection {

        private final String URL= "jdbc:mysql://";
        private String MASTERDB="key_master"; 
        private final String MASTERHOST="white";
        private Connection nCon;
        private Connection mCon;
        public String keyTable;
        public String key;
        public String host;
        public String db;
        private String user;
        private String password;

        /**
         * Create a ClusterConnection passing a key. 
         * @param db the database name
         * @param key the key name: e.g. asu_id
         * @param user the user name for connection to both master and nodes
         * @param password the password for connection to both master and nodes
         */
        public ClusterConnection (String db,String key, String user,String password) {
                loadMySQLDriver();
                setDb(db);
                setUser(user);
                setPassword(password);
                try {
                        // For nCon we create a connection to the master too. 
                        // This is just a place holder because the actual node connection is not created until we create the statement
                        // If we don't do this then when closing the two connections an exception might occurr because we try to close a non existing object
                        this.nCon = DriverManager.getConnection(URL+MASTERHOST+"/"+MASTERDB,user,password);
                        this.mCon = DriverManager.getConnection(URL+MASTERHOST+"/"+MASTERDB,user,password);
                }
                catch(SQLException e){
            System.err.println("SQLException: " + e.getMessage());
            System.err.println("SQLState:     " + e.getSQLState());
            System.err.println("VendorError:  " + e.getErrorCode());
                        System.err.println("Couldn't get connection to master host "+MASTERHOST+", db="+MASTERDB+", exiting.");
                        System.exit(2);                 
                }
                this.key=key; //can't use the setKey method here before we've got the db field initialized
                setKeyTable(db);
        }

        /**
         * Create a ClusterConnection without passing a key. The key will be set later when we call createStatement(key,idx) 
         * @param db the database name
         * @param user the user name for connection to both master and nodes
         * @param password the password for connection to both master and nodes
         */ 
        public ClusterConnection (String db, String user,String password) { 
                loadMySQLDriver();
                setDb(db);
                setUser(user);
                setPassword(password);
                try {
                        // For nCon we create a connection to the master too. 
                        // This is just a place holder because the actual node connection is not created until we create the statement
                        // If we don't do this then when closing the two connections an exception might occurr because we try to close a non existing object
                        this.nCon = DriverManager.getConnection(URL+MASTERHOST+"/"+MASTERDB,user,password);
                        this.mCon = DriverManager.getConnection(URL+MASTERHOST+"/"+MASTERDB,user,password);
                }
                catch(SQLException e){
            System.err.println("SQLException: " + e.getMessage());
            System.err.println("SQLState:     " + e.getSQLState());
            System.err.println("VendorError:  " + e.getErrorCode());
                        System.err.println("Couldn't get connection to master host "+MASTERHOST+", db="+MASTERDB+", exiting.");
                        System.exit(2);                 
                }
        }
        
        public void loadMySQLDriver() {
                try {
                        Class.forName("com.mysql.jdbc.Driver").newInstance();
                }
                catch(Exception e) {
                        System.err.println(e.getMessage());
                        System.err.println("An exception occurred while loading the mysql jdbc driver, exiting.");
                        System.exit(1);
                }
        }
        public void close() {
                try {
                        this.nCon.close();
                        this.mCon.close();
                }
                catch(SQLException e) {
                        System.err.println("Couldn't close database connections for master: "+MASTERHOST+" and node: "+this.host+", exiting.");
            System.err.println("SQLException: " + e.getMessage());
            System.err.println("SQLState:     " + e.getSQLState());
                        System.exit(3);                                         
                }
        }
        
        public String getHost4Idx (int idx) {
                String host="";
                Statement S;
                ResultSet R;
                try {
                        S=mCon.createStatement();
                        String query="SELECT client_name FROM "+keyTable+" AS m INNER JOIN clients_names AS c "+
                                                "ON (m.client_id=c.client_id) WHERE "+key+"="+idx+";";
                        R=S.executeQuery(query);
                        if (R.next()){
                                host=R.getString(1);
                        }
                        S.close();
                        R.close();
                }
                catch(SQLException e) {
                        System.err.println("Couldn't get the host name for idx "+idx+", exiting");
            System.err.println("SQLException: " + e.getMessage());
            System.err.println("SQLState:     " + e.getSQLState());
                        System.exit(3);                                                                 
                }
                return host;
        }
        
        public void setHostFromIdx(int idx){
                setHost(getHost4Idx(idx));
        }
        
        public void setHost(String host) {
                this.host=host;
                try {
                        //Closing previous connection is essential
                        //If we don't close it a lot of connections stay open after using a ClusterConnection object for a while
                        this.nCon.close(); 
                        this.nCon=DriverManager.getConnection(URL+host+"/"+db,user,password);
                }
                catch (SQLException e){
            System.err.println("SQLException: " + e.getMessage());
            System.err.println("SQLState:     " + e.getSQLState());
                        System.err.println("Couldn't get connection to node "+host+", database "+db+", exiting.");
                        System.exit(2);                                         
                }
        }
        
        /**
         * This method is strictly private. We shouldn't call this from another class as a key might not be set when we call it
         * and thus we can't get the client_id from the master key table. Only to be called from createStatement(key,idx)
         * @param idx the value of the id for a certain key already set
         * @return a Stament object with a connection to the node that contains idx for key
         */
        private Statement createStatement(int idx) { // to use when the field "key" is already set
                setKeyTable();
                Statement S=null;
                this.setHostFromIdx(idx);
                try {
                        S=this.nCon.createStatement();
                }
                catch (SQLException e){
                        System.err.println("SQLException: " + e.getMessage());
                        System.err.println("SQLState:     " + e.getSQLState());
                        System.err.println("Couldn't create statement for the node connection, idx= "+idx+", exiting.");
                        System.exit(2);                                                                 
                }
                return S;
        }
        
        /**
         * This method is used to create a statement passing the key and idx. It will create a connection the the right node 
         * and return a Statement for that connection
         * @param idx the key name
         * @param idx the id value for that key
         * @return a Statement object with a connection to the node that contains idx for key
         */
        public Statement createStatement(String key,int idx) {
                setKey(key);
                return createStatement(idx);
        }
        
        /**
         * To execute a sql update/insert query in the right node given a query, key and idx. Just a shortcut not to have to do the create statement and execute
         * @param query the SQL query
         * @param key the name of the key
         * @param idx the id value for that key
         */
        public void executeSql(String query,String key, int idx) {
                Statement stmt;
                try {
                    stmt = this.createStatement(key,idx);       
                    stmt.execute(query);
                        stmt.close();               
                } catch (SQLException e) {
                    System.err.println("SQLException: " + e.getMessage());
                    System.err.println("SQLState:     " + e.getSQLState());
                    System.err.println("VendorError:  " + e.getErrorCode());
                    e.printStackTrace();
                } 
        }
        /**
         * To change the MASTERDB String, i.e. the name of the key master database. To be used in testing.
         * @param db the name of the key master db we want to use instead of the default defined in the MASTERDB field
         */
        public void setKeyDb(String db) { 
                this.MASTERDB=db;
                try {
                        //Closing previous connection is essential
                        this.mCon.close(); 
                        this.mCon=DriverManager.getConnection(URL+MASTERHOST+"/"+MASTERDB,user,password);
                }
                catch (SQLException e){
            System.err.println("SQLException: " + e.getMessage());
            System.err.println("SQLState:     " + e.getSQLState());
                        System.err.println("Couldn't get connection to master host "+host+", database "+MASTERDB+", exiting.");
                        System.exit(2);                                         
                }
        }
        
        /**
         * To set keyTable field in constructor (i.e. first time). Only to be used in constructor.
         * @param db the database name
         */
        public void setKeyTable(String db) { 
                String query="SELECT key_master_table FROM dbs_keys WHERE db=\'"+db+"\' AND key_name=\'"+this.key+"\';";
                try {
                        Statement S = this.mCon.createStatement();
                        ResultSet R = S.executeQuery(query);
                        if (R.next()){
                                this.keyTable=R.getString(1);
                        }
                        R.close();
                        S.close();                      
                } catch (SQLException e) {
            System.err.println("SQLException: " + e.getMessage());
            System.err.println("SQLState:     " + e.getSQLState());
                        System.err.println("Couldn't get the key_master_table from "+MASTERDB+", exiting.");
                        System.exit(2);                                         
                }                               
        }
        
        /**
         * To set the keyTable field when db is already set
         * The value of keyTable is taken from the dbs_keys table in the database given the db and key.
         */
        public void setKeyTable() {  
                String query="SELECT key_master_table FROM dbs_keys WHERE db=\'"+this.db+"\' AND key_name=\'"+this.key+"\';";
                try {
                        Statement S = this.mCon.createStatement();
                        ResultSet R = S.executeQuery(query);
                        if (R.next()){
                                this.keyTable=R.getString(1);
                        }
                        R.close();
                        S.close();
                } catch (SQLException e) {
            System.err.println("SQLException: " + e.getMessage());
            System.err.println("SQLState:     " + e.getSQLState());
                        System.err.println("Couldn't get the key_master_table from "+MASTERDB+", exiting.");
                        System.exit(2);                                         
                }
        }
        
        public String getKeyTable() {
                return this.keyTable;
        }
        
        /**
         * To get the name of the target table where splitted data is stored in nodes, e.g. for keyTable pdbgraph__asu_list, we get asu_list
         * @return
         */
        public String getTableOnNode(){
                String table="";
                if (this.keyTable.contains("__")) {
                        String[] tokens=this.keyTable.split("__");
                        table=tokens[1];
                }
                else {
                        System.err.println("Error! The keyTable field is not set in this ClusterConnection object.");
                }
                return table;
        }
        
        public void setUser(String user) {
                this.user=user;
        }

        public void setPassword(String password) {
                this.password=password;
        }
        
        public void setDb(String db){
                this.db=db;
        }
        
        public void setKey(String key){
                this.key=key;
                setKeyTable();
        }

        public Statement createMasterStatement() { 
                Statement S=null;
                try {
                        S=this.mCon.createStatement();
                }
                catch (SQLException e){
                        System.err.println("SQLException: " + e.getMessage());
                        System.err.println("SQLState:     " + e.getSQLState());
                        System.err.println("Couldn't create statement for the master connection, exiting.");
                        System.exit(2);                                                                 
                }
                return S;
        }
        
        public void createNewKeyMasterTbl(String table) {
                String keyMasterTbl=db+"__"+table;
                try {
                        String query="CREATE TABLE IF NOT EXISTS "+keyMasterTbl+" ("+
                                                key+" int(11) NOT NULL auto_increment, " +
                                                "client_id smallint(6) NOT NULL default '0', " +
                                                "PRIMARY KEY (`"+key+"`) " +
                                                ") ENGINE=MyISAM DEFAULT CHARSET=ascii COLLATE=ascii_bin;";
                        Statement S=this.mCon.createStatement();
                        S.executeUpdate(query);
                        S.close();
                } catch (SQLException e) {
                        System.err.println("Couldn't create table "+keyMasterTbl);
                        e.printStackTrace();
                }
                try {
                        Statement S=this.mCon.createStatement();
                        // following query is exactly the same as query in key_master.sql for key_master database definition
                        String query = "INSERT INTO dbs_keys "+
                                                "SELECT i.COLUMN_NAME AS key_name, LEFT(i.TABLE_NAME,POSITION('__' IN i.TABLE_NAME)-1) AS db, i.TABLE_NAME AS key_master_table "+
                                                "FROM INFORMATION_SCHEMA.STATISTICS AS i "+
                                                "WHERE i.TABLE_SCHEMA='"+MASTERDB+"' AND i.TABLE_NAME!='clients_names' AND i.TABLE_NAME!='dbs_keys';";
                        S.executeUpdate(query);
                        S.close();
                } catch (SQLException e) {
                        System.err.println("Didn't insert new record into table dbs_keys of database: "+MASTERDB+". The record for key: "+key+", table: "+table+" existed already. This is usually a harmless error!");
                        System.err.println("SQLException: " + e.getMessage());
                }
                setKeyTable();
        }

        public int[] getAllIdxFromMaster(String key) { 
                this.setKey(key);
                int[] ids=null;
                ArrayList<Integer> idsAL=new ArrayList<Integer>();
                try {                   
                        String query="SELECT "+key+" FROM "+keyTable+";";
                        Statement S=this.mCon.createStatement();
                        ResultSet R=S.executeQuery(query);
                        while (R.next()){
                                idsAL.add(R.getInt(1));
                        }
                        R.close();
                        S.close();
                }
                catch (SQLException e){
                        System.err.println("SQLException: " + e.getMessage());
                        System.err.println("SQLState:     " + e.getSQLState());
                        System.err.println("Couldn't get all indices from columnn "+key+" in table "+keyTable+" from "+MASTERDB+" database in "+MASTERHOST+", exiting.");
                        System.exit(2);                                                                 
                }
                ids=new int[idsAL.size()];
                for (int i=0;i<idsAL.size();i++){
                        ids[i]=idsAL.get(i);
                }
                return ids;
        }
        /**
         * To get all ids and clients_names pairs for a certain key. Useful when need to submit to all hosts using qsub -q
         * @param key the name of the key
         * @return HashMap with keys = indices, and values = node names where the corresponding index is stored
         */
        public HashMap<Integer,String> getAllIdxAndClients (String key){
                this.setKey(key);
                HashMap<Integer,String> idsAndClients=new HashMap<Integer,String>();
                try {
                        String query="SELECT a."+key+",c.client_name FROM "+keyTable+" AS a INNER JOIN clients_names AS c ON (a.client_id=c.client_id);";
                        Statement S=this.mCon.createStatement();
                        ResultSet R=S.executeQuery(query);
                        while (R.next()){
                                idsAndClients.put(R.getInt(1),R.getString(2));
                        }
                        R.close();
                        S.close();
                }
                catch (SQLException e){
                        System.err.println("SQLException: " + e.getMessage());
                        System.err.println("SQLState:     " + e.getSQLState());
                        System.err.println("Couldn't get all indices/client_names pairs from table "+keyTable+" from "+MASTERDB+" database in "+MASTERHOST+", exiting.");
                        System.exit(2);                                                                 
                }
                return idsAndClients;
        }
        
        /**
         * To get client_id for a certain idx and key
         * @param key the key name
         * @param idx the id value for that key
         * @return the client_id for node that has the data for the idx for that key
         */
        //TODO will need to change the query. In general this method would return more than 1 client_id if the idx is not unique
        public int getHostId4Idx (String key,int idx) { 
                int hostId=0;
                this.setKey(key);
                Statement S;
                ResultSet R;
                String query;
                int countCids=0;
                try {
                        S=mCon.createStatement();
                        query="SELECT count(client_id) FROM "+keyTable+" WHERE "+key+"="+idx+";";
                        R=S.executeQuery(query);
                        if (R.next()){
                                countCids=R.getInt(1);
                        }
                        if (countCids!=1){
                                System.err.println("the query was: "+query);
                                System.err.println("Error! the count of client_ids for idx "+key+"= "+idx+" is " +countCids+
                                                ". It must be 1! The values were taken from host: "+MASTERHOST+", database: "+MASTERDB+", table: "+keyTable+". Check what's wrong! Exiting now.");
                                System.exit(2);
                        }
                        else {
                                query="SELECT client_id FROM "+keyTable+" WHERE "+key+"="+idx+";";
                                R=S.executeQuery(query);
                                if (R.next()){
                                        hostId=R.getInt(1);
                                }
                        }
                        S.close();
                        R.close();
                }
                catch(SQLException e) {
                        System.err.println("Couldn't get the host id for idx "+key+"="+idx+", exiting");
            System.err.println("SQLException: " + e.getMessage());
            System.err.println("SQLState:     " + e.getSQLState());
                        System.exit(3);                                                                 
                }
                return hostId;
        }
        
        public void insertIdxInMaster(String key, int clientId) {
                Statement S;
                String query;
                this.setKey(key);
                try {
                        S=this.mCon.createStatement();
                        query="INSERT INTO "+this.keyTable+" (client_id) VALUES ("+clientId+");";
                        S.executeUpdate(query);
                        S.close();
                } 
                catch (SQLException E) {
                        System.err.println("SQLException: " + E.getMessage());
                        System.err.println("SQLState:     " + E.getSQLState());
                        System.err.println("Couldn't insert new "+this.key+" in master table "+this.getKeyTable()+". The client_id for it was "+clientId+". Exiting.");
                        System.exit(2);
                } 
        }

        public void insertIdxInMaster(String keySrc,String keyDest,int idxSrc) {
                this.setKey(keySrc);
                int clientId=0;
                clientId=this.getHostId4Idx(keySrc,idxSrc);
                insertIdxInMaster(keyDest,clientId);
        }

        public int getLastInsertId(String key) {
                int lastIdx=0;
                this.setKey(key);
                Statement S;
                ResultSet R;
                String query = "";
                try {
                        S = this.mCon.createStatement();
                        query = "SELECT LAST_INSERT_ID() FROM "+this.keyTable+" LIMIT 1;";
                        R = S.executeQuery(query);
                        if (R.next()) {
                                lastIdx=R.getInt(1);
                        }
                        R.close();
                        S.close();
                } 
                catch (SQLException E) {
                        System.err.println("Couldn't get the last insert id for key type "+this.key+" from table "+this.keyTable+". Exiting");
                        System.err.println("SQLException: " + E.getMessage());
                        System.err.println("SQLState:     " + E.getSQLState());
                        System.exit(3);
                } // end try/catch connection 
                return lastIdx;
        } // end getGraphId
        
        public int[][] getIdxSet(String key) { 
                int[][] indMatrix=null;
                this.setKey(key);
                String query;
                Statement S;
                ResultSet R;
                try {
                        // STEP 1 -- getting set of all client_ids
                        S=this.mCon.createStatement();
                        query="SELECT count(distinct client_id) FROM "+keyTable+";";
                        int count=0;
                        R=S.executeQuery(query);
                        if (R.next()){
                                count=R.getInt(1);
                        }
                        query="SELECT DISTINCT client_id FROM "+keyTable+" ORDER BY client_id;";
                        //R.close();
                        //S.close();
                        R=S.executeQuery(query);
                        
                        // STEP 2 -- putting sets of indices counts into temp tables c_<client_id> with a serial auto_increment field
                        int[] clids=new int[count]; //array to store all client_ids. To be used in loops later
                        int i=0;
                        while (R.next()){
                                Statement Sloop=this.mCon.createStatement();
                                int clid=R.getInt(1);
                                query="CREATE TEMPORARY TABLE c_"+clid+" (serial int(11) NOT NULL AUTO_INCREMENT,"+key+" int(11),client_id int(11), PRIMARY KEY(serial));";                             
                                Sloop.executeUpdate(query);
                                query="INSERT INTO c_"+clid+" ("+key+",client_id) SELECT "+key+",client_id FROM "+keyTable+" WHERE client_id="+clid+";";
                                Sloop.executeUpdate(query);
                                clids[i]=clid;
                                i++;
                                Sloop.close();
                        }
                        
                        // STEP3 -- merging all c_<client_id> tables into a temp table tmp_allcs and selecting the client_id with the maximum count
                        //query="SELECT client_id,count(*) as c FROM c_34 GROUP BY client_id UNION SELECT client_id,count(*) as c FROM c_32 GROUP BY client_id;";
                        query="DROP TABLE IF EXISTS tmp_allcs;"; 
                        S.executeUpdate(query);
                        //this table must be permanent! otherwise cannot do the select max(c) later
                        query="CREATE TABLE IF NOT EXISTS tmp_allcs (client_id int(11), c int(11)) ENGINE=MEMORY;";
                        S.executeUpdate(query);
                        String unionStr="SELECT client_id,count(*) AS c FROM c_"+clids[0]+" GROUP BY client_id";
                        for (i=1;i<clids.length;i++) {
                                unionStr+=" UNION SELECT client_id,count(*) AS c FROM c_"+clids[i]+" GROUP BY client_id";
                        }
                        query="INSERT INTO tmp_allcs "+unionStr+";";
                        S.executeUpdate(query);
                        query="SELECT client_id,c FROM tmp_allcs WHERE c=(SELECT max(c) FROM tmp_allcs);";
                        R=S.executeQuery(query);
                        int clidMaxIdxCount=0;
                        int maxIdxCount=0;
                        if (R.next()) {
                                clidMaxIdxCount=R.getInt(1);
                                maxIdxCount=R.getInt(2);
                        }
                        query="DROP TABLE tmp_allcs;";
                        S.executeUpdate(query);
                        
                        // STEP 4 -- join all c_<client_id> tables into a table with a serial column, and c_<client_id> columns each of them with the indices for each client_id 
                        //query="SELECT c_34.serial,c_34.asu_id AS c_34,c_32.asu_id AS c_32,c_36.asu_id AS c_36 FROM c_34 LEFT JOIN c_32 ON (c_34.serial=c_32.serial) LEFT JOIN c_36 ON (c_34.serial=c_36.serial);";
                        String selectStr="c_"+clidMaxIdxCount+".serial, c_"+clidMaxIdxCount+"."+key+" AS c_"+clidMaxIdxCount;
                        String fromStr="c_"+clidMaxIdxCount;
                        for (i=0;i<clids.length;i++) {
                                if (clids[i]!=clidMaxIdxCount){
                                        selectStr+=", c_"+clids[i]+"."+key+" AS c_"+clids[i];
                                        fromStr+=" LEFT JOIN c_"+clids[i]+" ON (c_"+clidMaxIdxCount+".serial=c_"+clids[i]+".serial)";
                                }
                        } 
                        query="CREATE TEMPORARY TABLE indices_matrix "+"SELECT "+selectStr+" FROM "+fromStr+";";
                        S.executeUpdate(query);
                        
                        // STEP 5 -- put the table into a 2-dimensional array and return it
                        indMatrix = new int[maxIdxCount][clids.length];
                        query="SELECT * FROM indices_matrix";
                        R=S.executeQuery(query);
                        i=0;
                        while (R.next()) {
                                for (int j=0;j<clids.length;j++){
                                        indMatrix[i][j]=R.getInt(j+2);
                                }
                                i++;
                        }
                        R.close();
                        S.close();
                }
                catch (SQLException e){
                        System.err.println("SQLException: " + e.getMessage());
                        System.err.println("SQLState:     " + e.getSQLState());
                        System.err.println("Couldn't get the indices set from columnn "+key+" in table "+keyTable+" from "+MASTERDB+" database in "+MASTERHOST+", exiting.");
                        System.exit(2);                                                                 
                }
                return indMatrix;
        }

        
}
Revision:	76
Committed:	Tue Apr 11 16:00:26 2006 UTC (18 years, 5 months ago) by duarte
File size:	20993 byte(s)
Log Message:	Minor change, in getHostId4Ifx one of the error messages was being written to out, now to err