Why is there no error when checkpointing after db log files are removed?

Question

I would like to test a scenario when an application's embedded database is corrupted somehow. The simplest test I could think of was removing the database log files while the application is running. However, I can't seem to get any failure. To demonstrate, below is a code snippet that demonstrates what I am trying to do. (I am using JE 3.3.75 on Mac OS 10.5.6):
public class FileRemovalTest {
public static void main(String[] args) throws Exception
// Setup the DB Environment
EnvironmentConfig ec = new EnvironmentConfig();
ec.setAllowCreate(true);
ec.setTransactional(true);
ec.setConfigParam(EnvironmentConfig.ENV_RUN_CLEANER, "false");
ec.setConfigParam(EnvironmentConfig.ENV_RUN_CHECKPOINTER, "false");
ec.setConfigParam(EnvironmentConfig.CLEANER_EXPUNGE, "true");
ec.setConfigParam("java.util.logging.FileHandler.on", "true");
ec.setConfigParam("java.util.logging.level", "FINEST");
Environment env = new Environment(new File("."), ec);
// Create a database
DatabaseConfig dbConfig = new DatabaseConfig();
dbConfig.setAllowCreate(true);
dbConfig.setTransactional(true);
Database db = env.openDatabase(null, "test", dbConfig);
// Insert an entry and checkpoint the database
db.put(
null,
new DatabaseEntry("key".getBytes()),
new DatabaseEntry("value".getBytes()));
CheckpointConfig checkpointConfig = new CheckpointConfig();
checkpointConfig.setForce(true);
env.checkpoint(checkpointConfig);
// Delete the DB log files
File[] dbFiles = new File(".").listFiles(new DbFilenameFilter());
if (dbFiles != null)
for (File file : dbFiles)
file.delete();
// Add another entry and checkpoint the database again.
db.put(
null,
new DatabaseEntry("key2".getBytes()),
new DatabaseEntry("value2".getBytes())
{color:#ff0000} *// Q: Why does this 'put' succeed?*
{color}
env.checkpoint(checkpointConfig);
{color:#ff0000}*// Q: Why does this checkpoint succeed?*{color}
// Close the database and the environment
db.close();
env.close();
private static class DbFilenameFilter implements FilenameFilter
public boolean accept(File dir, String name) {
return name.endsWith(".jdb");
This is what I see in the logs:
2009-03-05 12:53:30:631:CST CONFIG Recovery w/no files.
2009-03-05 12:53:30:677:CST FINER Ins: bin=2 ln=1 lnLsn=0x0/0xe9 index=0
2009-03-05 12:53:30:678:CST FINER Ins: bin=5 ln=4 lnLsn=0x0/0x193 index=0
2009-03-05 12:53:30:688:CST FINE Commit:id = 1 numWriteLocks=1 numReadLocks = 0
2009-03-05 12:53:30:690:CST FINEST size interval=0 lastCkpt=0x0/0x0 time interval=0 force=true runnable=true
2009-03-05 12:53:30:703:CST FINER Ins: bin=8 ln=7 lnLsn=0x0/0x48b index=0
2009-03-05 12:53:30:704:CST CONFIG Checkpoint 1: source=recovery success=true nFullINFlushThisRun=4 nDeltaINFlushThisRun=0
2009-03-05 12:53:30:705:CST CONFIG Recovery finished: Recovery Infonull> useMinReplicatedNodeId=0 useMaxNodeId=0 useMinReplicatedDbId=0 useMaxDbId=0 useMinReplicatedTxnId=0 useMaxTxnId=0 numMapINs=0 numOtherINs=0 numBinDeltas=0 numDuplicateINs=0 lnFound=0 lnNotFound=0 lnInserted=0 lnReplaced=0 nRepeatIteratorReads=0
2009-03-05 12:53:30:709:CST FINEST Environment.open: name=test dbConfig=allowCreate=true
exclusiveCreate=false
transactional=true
readOnly=false
duplicatesAllowed=false
deferredWrite=false
temporary=false
keyPrefixingEnabled=false
2009-03-05 12:53:30:713:CST FINER Ins: bin=2 ln=10 lnLsn=0x0/0x7be index=1
2009-03-05 12:53:30:714:CST FINER Ins: bin=5 ln=11 lnLsn=0x0/0x820 index=1
2009-03-05 12:53:30:718:CST FINE Commit:id = 2 numWriteLocks=0 numReadLocks = 0
2009-03-05 12:53:30:722:CST FINEST Database.put key=107 101 121 data=118 97 108 117 101
2009-03-05 12:53:30:728:CST FINER Ins: bin=13 ln=12 lnLsn=0x0/0x973 index=0
2009-03-05 12:53:30:729:CST FINE Commit:id = 3 numWriteLocks=1 numReadLocks = 0
2009-03-05 12:53:30:729:CST FINEST size interval=0 lastCkpt=0x0/0x581 time interval=0 force=true runnable=true
2009-03-05 12:53:30:735:CST FINER Mod: bin=5 ln=4 lnIdx=0 oldLnLsn=0x0/0x193 newLnLsn=0x0/0xb61
2009-03-05 12:53:30:736:CST FINER Mod: bin=5 ln=11 lnIdx=1 oldLnLsn=0x0/0x820 newLnLsn=0x0/0xc3a
2009-03-05 12:53:30:737:CST FINER Ins: bin=8 ln=15 lnLsn=0x0/0xd38 index=0
2009-03-05 12:53:30:738:CST CONFIG Checkpoint 2: source=api success=true nFullINFlushThisRun=6 nDeltaINFlushThisRun=0
2009-03-05 12:53:30:741:CST FINEST Database.put key=107 101 121 50 data=118 97 108 117 101 50
2009-03-05 12:53:30:742:CST FINER Ins: bin=13 ln=16 lnLsn=0x0/0xeaf index=1
2009-03-05 12:53:30:743:CST FINE Commit:id = 4 numWriteLocks=1 numReadLocks = 0
2009-03-05 12:53:30:744:CST FINEST size interval=0 lastCkpt=0x0/0xe32 time interval=0 force=true runnable=true
2009-03-05 12:53:30:746:CST FINER Mod: bin=5 ln=4 lnIdx=0 oldLnLsn=0x0/0xb61 newLnLsn=0x0/0x1166
2009-03-05 12:53:30:747:CST FINER Mod: bin=5 ln=11 lnIdx=1 oldLnLsn=0x0/0xc3a newLnLsn=0x0/0x11e9
2009-03-05 12:53:30:748:CST FINER Ins: bin=8 ln=17 lnLsn=0x0/0x126c index=0
2009-03-05 12:53:30:748:CST CONFIG Checkpoint 3: source=api success=true nFullINFlushThisRun=4 nDeltaINFlushThisRun=0
2009-03-05 12:53:30:750:CST FINEST Database.close: name=test
2009-03-05 12:53:30:751:CST FINE Close of environment . started
2009-03-05 12:53:30:751:CST FINEST size interval=0 lastCkpt=0x0/0x1363 time interval=0 force=true runnable=true
2009-03-05 12:53:30:754:CST FINER Mod: bin=5 ln=4 lnIdx=0 oldLnLsn=0x0/0x1166 newLnLsn=0x0/0x14f8
2009-03-05 12:53:30:755:CST FINER Mod: bin=5 ln=11 lnIdx=1 oldLnLsn=0x0/0x11e9 newLnLsn=0x0/0x15a9
2009-03-05 12:53:30:756:CST FINER Ins: bin=8 ln=18 lnLsn=0x0/0x16ab index=0
2009-03-05 12:53:30:757:CST CONFIG Checkpoint 4: source=close success=true nFullINFlushThisRun=4 nDeltaINFlushThisRun=0
2009-03-05 12:53:30:757:CST FINE About to shutdown daemons for Env .

Answer 1

Hi,
OS X, being Unix-like, probably isn't actually deleting file 00000000.jdb since JE still has it open -- the file deletion is deferred until it is closed. JE keeps N files open, where N is configurable.
We do corruption testing ourselves, in the following test by overwriting a file and then attempting to read back the entire database:
test/com/sleepycat/je/util/DbScavengerTest.java
--mark