/**
* This will look through the completed_txn_components table and look for partitions or tables
* that may be ready for compaction. Also, look through txns and txn_components tables for aborted
* transactions that we should add to the list.
*
* @param maxAborted Maximum number of aborted queries to allow before marking this as a potential
* compaction.
* @return list of CompactionInfo structs. These will not have id, type, or runAs set since these
* are only potential compactions not actual ones.
*/
public Set<CompactionInfo> findPotentialCompactions(int maxAborted) throws MetaException {
Connection dbConn = getDbConn();
Set<CompactionInfo> response = new HashSet<CompactionInfo>();
try {
Statement stmt = dbConn.createStatement();
// Check for completed transactions
String s =
"select distinct ctc_database, ctc_table, "
+ "ctc_partition from COMPLETED_TXN_COMPONENTS";
LOG.debug("Going to execute query <" + s + ">");
ResultSet rs = stmt.executeQuery(s);
while (rs.next()) {
CompactionInfo info = new CompactionInfo();
info.dbname = rs.getString(1);
info.tableName = rs.getString(2);
info.partName = rs.getString(3);
response.add(info);
}
// Check for aborted txns
s =
"select tc_database, tc_table, tc_partition "
+ "from TXNS, TXN_COMPONENTS "
+ "where txn_id = tc_txnid and txn_state = '"
+ TXN_ABORTED
+ "' "
+ "group by tc_database, tc_table, tc_partition "
+ "having count(*) > "
+ maxAborted;
LOG.debug("Going to execute query <" + s + ">");
rs = stmt.executeQuery(s);
while (rs.next()) {
CompactionInfo info = new CompactionInfo();
info.dbname = rs.getString(1);
info.tableName = rs.getString(2);
info.partName = rs.getString(3);
info.tooManyAborts = true;
response.add(info);
}
LOG.debug("Going to rollback");
dbConn.rollback();
} catch (SQLException e) {
LOG.error("Unable to connect to transaction database " + e.getMessage());
} finally {
closeDbConn(dbConn);
}
return response;
}
