/**
* Find entries in the queue that are ready to be cleaned.
*
* @return information on the entry in the queue.
*/
public List<CompactionInfo> findReadyToClean() throws MetaException {
Connection dbConn = getDbConn();
List<CompactionInfo> rc = new ArrayList<CompactionInfo>();
try {
Statement stmt = dbConn.createStatement();
String s =
"select cq_id, cq_database, cq_table, cq_partition, "
+ "cq_type, cq_run_as from COMPACTION_QUEUE where cq_state = '"
+ READY_FOR_CLEANING
+ "'";
LOG.debug("Going to execute query <" + s + ">");
ResultSet rs = stmt.executeQuery(s);
while (rs.next()) {
CompactionInfo info = new CompactionInfo();
info.id = rs.getLong(1);
info.dbname = rs.getString(2);
info.tableName = rs.getString(3);
info.partName = rs.getString(4);
switch (rs.getString(5).charAt(0)) {
case MAJOR_TYPE:
info.type = CompactionType.MAJOR;
break;
case MINOR_TYPE:
info.type = CompactionType.MINOR;
break;
default:
throw new MetaException("Unexpected compaction type " + rs.getString(5));
}
info.runAs = rs.getString(6);
rc.add(info);
}
LOG.debug("Going to rollback");
dbConn.rollback();
return rc;
} catch (SQLException e) {
LOG.error("Unable to select next element for cleaning, " + e.getMessage());
try {
LOG.debug("Going to rollback");
dbConn.rollback();
} catch (SQLException e1) {
}
throw new MetaException(
"Unable to connect to transaction database " + StringUtils.stringifyException(e));
} finally {
closeDbConn(dbConn);
}
}
/**
* This will grab the next compaction request off of the queue, and assign it to the worker.
*
* @param workerId id of the worker calling this, will be recorded in the db
* @return an info element for this compaction request, or null if there is no work to do now.
*/
public CompactionInfo findNextToCompact(String workerId) throws MetaException {
try {
Connection dbConn = getDbConn();
CompactionInfo info = new CompactionInfo();
try {
Statement stmt = dbConn.createStatement();
String s =
"select cq_id, cq_database, cq_table, cq_partition, "
+ "cq_type from COMPACTION_QUEUE where cq_state = '"
+ INITIATED_STATE
+ "' for update";
LOG.debug("Going to execute query <" + s + ">");
ResultSet rs = stmt.executeQuery(s);
if (!rs.next()) {
LOG.debug("No compactions found ready to compact");
dbConn.rollback();
return null;
}
info.id = rs.getLong(1);
info.dbname = rs.getString(2);
info.tableName = rs.getString(3);
info.partName = rs.getString(4);
switch (rs.getString(5).charAt(0)) {
case MAJOR_TYPE:
info.type = CompactionType.MAJOR;
break;
case MINOR_TYPE:
info.type = CompactionType.MINOR;
break;
default:
throw new MetaException("Unexpected compaction type " + rs.getString(5));
}
// Now, update this record as being worked on by this worker.
long now = System.currentTimeMillis();
s =
"update COMPACTION_QUEUE set cq_worker_id = '"
+ workerId
+ "', "
+ "cq_start = "
+ now
+ ", cq_state = '"
+ WORKING_STATE
+ "' where cq_id = "
+ info.id;
LOG.debug("Going to execute update <" + s + ">");
if (stmt.executeUpdate(s) != 1) {
LOG.error("Unable to update compaction record");
LOG.debug("Going to rollback");
dbConn.rollback();
}
LOG.debug("Going to commit");
dbConn.commit();
return info;
} catch (SQLException e) {
LOG.error("Unable to select next element for compaction, " + e.getMessage());
try {
LOG.debug("Going to rollback");
dbConn.rollback();
} catch (SQLException e1) {
}
detectDeadlock(e, "findNextToCompact");
throw new MetaException(
"Unable to connect to transaction database " + StringUtils.stringifyException(e));
} finally {
closeDbConn(dbConn);
}
} catch (DeadlockException e) {
return findNextToCompact(workerId);
} finally {
deadlockCnt = 0;
}
}