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Human-readable metadata scan #6519

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2 changes: 1 addition & 1 deletion core/src/main/java/org/apache/accumulo/core/metadata/StoredTabletFile.java
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Original file line number Diff line number Diff line change
Expand Up @@ -150,7 +150,7 @@ public int hashCode() {

@Override
public String toString() {
return metadataEntry;
return toMinimalString();

@phrocker phrocker Aug 31, 2026

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Wouldn't this affect every log line and exception message that stringifies . Would this create some kind of diagnostics regression if anyone is consuming logs for alterting? Should this be moved to the call sites that need it?

@dlmarion dlmarion Aug 31, 2026

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That's where I was going with my other comment. If this change was only made to support the logging change, then I think it should be reverted. I don't think logging changes are an issue for the 4.0 release, but I'm more concerned about some code using the output of toString by mistake and the unintended consequences of changing it.

@phrocker phrocker Aug 31, 2026 •
edited
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I was less concerned about programmatic usage and more concerned about logs given how they could be used in cloud deployments -- but I think the end result is the same: if the fidelity is changing as a result of this change would any downstream consumer have to change processes?

If the answer is yes, then is the ROI of this change in its favor ?

@phrocker phrocker Aug 31, 2026

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I should use AI to comment so I don't have so many typos...

}

public static StoredTabletFile of(final Text metadataEntry) {
Expand Down
54 changes: 53 additions & 1 deletion shell/src/main/java/org/apache/accumulo/shell/commands/ScanCommand.java
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Original file line number Diff line number Diff line change
Expand Up @@ -21,6 +21,7 @@
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Map.Entry;
Expand All @@ -40,7 +41,11 @@
import org.apache.accumulo.core.data.Range;
import org.apache.accumulo.core.data.Value;
import org.apache.accumulo.core.iterators.SortedKeyValueIterator;
import org.apache.accumulo.core.metadata.StoredTabletFile;
import org.apache.accumulo.core.metadata.SystemTables;
import org.apache.accumulo.core.metadata.schema.MetadataSchema;
import org.apache.accumulo.core.security.Authorizations;
import org.apache.accumulo.core.util.format.DefaultFormatter;
import org.apache.accumulo.core.util.format.Formatter;
import org.apache.accumulo.core.util.format.FormatterConfig;
import org.apache.accumulo.shell.Shell;
Expand Down Expand Up @@ -75,6 +80,7 @@ public class ScanCommand extends Command {
protected Option contextOpt;
private Option executionHintsOpt;
private Option scanServerOpt;
private Option decodeMetadataOpt;

protected void setupSampling(final String tableName, final CommandLine cl, final Shell shellState,
ScannerBase scanner)
Expand Down Expand Up @@ -155,12 +161,54 @@ public int execute(final String fullCommand, final CommandLine cl, final Shell s
Shell.log.error("Invalid length argument", iae);
}
}
printRecords(cl, shellState, config, scanner, formatter, printFile);
boolean decodeMetadata = cl.hasOption(decodeMetadataOpt.getLongOpt())
&& (tableName.equals(SystemTables.METADATA.tableName())
|| tableName.equals(SystemTables.ROOT.tableName()));

if (decodeMetadata) {
printRecordsWithDecodedRanges(cl, shellState, config, scanner, printFile);
} else {
printRecords(cl, shellState, config, scanner, formatter, printFile);
}
}

return 0;
}

private void printRecordsWithDecodedRanges(final CommandLine cl, final Shell shellState,
final FormatterConfig config, final Scanner scanner, final PrintFile printFile)
throws IOException {

final Text fileCf = new Text(MetadataSchema.TabletsSection.DataFileColumnFamily.STR_NAME);
final Text scanCf = new Text(MetadataSchema.TabletsSection.ScanFileColumnFamily.STR_NAME);

final List<String> lines = new ArrayList<>();

for (Entry<Key,Value> entry : scanner) {
Text cf = entry.getKey().getColumnFamily();

if (fileCf.equals(cf) || scanCf.equals(cf)) {
String metadataRow = entry.getKey().getRow().toString();
String cq = entry.getKey().getColumnQualifier().toString();
try {
StoredTabletFile stf = StoredTabletFile.of(cq);
lines.add(metadataRow + "\t" + stf.toMinimalString());
} catch (RuntimeException e) {
lines.add(DefaultFormatter.formatEntry(entry, config));
}
} else {
// All non-file columns (loc:, srv:, ~tab:, etc.) use normal formatting
lines.add(DefaultFormatter.formatEntry(entry, config));
}
}

if (printFile == null) {
shellState.printLines(lines.iterator(), !cl.hasOption(disablePaginationOpt.getOpt()));
} else {
shellState.printLines(lines.iterator(), false, printFile);
}
}

protected boolean getUseSample(CommandLine cl) {
return cl.hasOption(sampleOpt.getLongOpt());
}
Expand Down Expand Up @@ -352,6 +400,8 @@ public Options getOptions() {
executionHintsOpt = new Option(null, "execution-hints", true, "Execution hints map");
scanServerOpt =
new Option("cl", "consistency-level", true, "set consistency level (experimental)");
decodeMetadataOpt = new Option("dm", "decode-metadata", false,

@dlmarion dlmarion Aug 31, 2026

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I'm not sure that we need an option. If the user has the ability to scan the metadata, then we should just show them the un-obfuscated metadata entry.

@phrocker phrocker Aug 31, 2026 •
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Doesn't accumulo already have formatters? metadataformatter that extends default formatter could be a better option and obviate the need for an option. also could be default?

@dlmarion dlmarion Aug 31, 2026

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It's a good idea, but I think the intention is to remove formatters. See #3265.

@phrocker phrocker Aug 31, 2026 •
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Yes, thank you. I encountered this last year sometime when testing 4.0, but I have a very poor memory....

Should this option be flipped? On by default, old method an option just in case someone relies on the encoded form?

I think it's pretty fair to say 4.0 changes the output, though.

"Decode fenced file row ranges from metadata and root tables");

scanOptAuths.setArgName("comma-separated-authorizations");
scanOptRow.setArgName("row");
Expand All @@ -366,6 +416,7 @@ public Options getOptions() {
contextOpt.setArgName("context");
executionHintsOpt.setArgName("<key>=<value>{,<key>=<value>}");
scanServerOpt.setArgName("immediate|eventual");
decodeMetadataOpt.setArgName("decode-metadata");

profileOpt = new Option("pn", "profile", true, "iterator profile name");
profileOpt.setArgName("profile");
Expand Down Expand Up @@ -398,6 +449,7 @@ public Options getOptions() {
o.addOption(contextOpt);
o.addOption(executionHintsOpt);
o.addOption(scanServerOpt);
o.addOption(decodeMetadataOpt);

return o;
}
Expand Down
5 changes: 2 additions & 3 deletions test/src/main/java/org/apache/accumulo/test/util/FileMetadataUtil.java
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Original file line number Diff line number Diff line change
Expand Up @@ -68,9 +68,8 @@ public class FileMetadataUtil {
StoredTabletFile file = fileEntry.getKey();
DataFileValue dfv = fileEntry.getValue();
files.put(file, dfv);
log.debug("Extent: " + tabletMetadata.getExtent() + "; File Name: " + file.getFileName()
+ "; Range: " + file.getRange() + "; Entries: " + dfv.getNumEntries() + ", Size: "
+ dfv.getSize());
log.debug("Extent: {}; File: {}; Entries: {}; Size: {}", tabletMetadata.getExtent(), file,

@dlmarion dlmarion Aug 31, 2026

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Was the change above in StoredTabletFile.toString() made to support just using file here in the log output in place of file.getFileName() and file.getRange()?

dfv.getNumEntries(), dfv.getSize());
i++;
}
}
Expand Down