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fix(metrics): Do not flush when no metrics were added to avoid printing root-level _aws dict #1891

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Merged
merged 2 commits into from
Jun 16, 2025
Merged

fix(metrics): Do not flush when no metrics were added to avoid printing root-level _aws dict #1891

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4fcbf3c
fix(metrics): Do not flush when no metrics were added to avoid printi…
phipag Jun 16, 2025
3b035d9
Fix pmd linting failures.
phipag Jun 16, 2025
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3 changes: 2 additions & 1 deletion ...cs/src/main/java/software/amazon/lambda/powertools/metrics/internal/EmfMetricsLogger.java
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Original file line number Diff line number Diff line change
Expand Up @@ -81,9 +81,9 @@
emfDimensionSet.addDimension(key, val);
// Update our local copy of default dimensions
defaultDimensions.put(key, val);
} catch (Exception e) {
// Ignore dimension errors
}

Check failure on line 86 in powertools-metrics/src/main/java/software/amazon/lambda/powertools/metrics/internal/EmfMetricsLogger.java

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GitHub Actions / pmd_analyse

Avoid empty catch blocks 

Empty Catch Block finds instances where an exception is caught, but nothing is done.
In most circumstances, this swallows an exception which should either be acted on
or reported.

EmptyCatchBlock (Priority: 1, Ruleset: Error Prone)
https://docs.pmd-code.org/pmd-doc-7.14.0/pmd_rules_java_errorprone.html#emptycatchblock
});

emfLogger.putDimensions(emfDimensionSet);
Expand All @@ -105,9 +105,9 @@
dimensions.forEach((key, value) -> {
try {
emfDimensionSet.addDimension(key, value);
} catch (Exception e) {
// Ignore dimension errors
}

Check failure on line 110 in powertools-metrics/src/main/java/software/amazon/lambda/powertools/metrics/internal/EmfMetricsLogger.java

View workflow job for this annotation

GitHub Actions / pmd_analyse

Avoid empty catch blocks 

Empty Catch Block finds instances where an exception is caught, but nothing is done.
In most circumstances, this swallows an exception which should either be acted on
or reported.

EmptyCatchBlock (Priority: 1, Ruleset: Error Prone)
https://docs.pmd-code.org/pmd-doc-7.14.0/pmd_rules_java_errorprone.html#emptycatchblock
});
emfLogger.setDimensions(emfDimensionSet);
// Store a copy of the default dimensions
Expand Down Expand Up @@ -164,8 +164,9 @@
} else {
LOGGER.warn("No metrics were emitted");
}
} else {
emfLogger.flush();
}
emfLogger.flush();
}

@Override
Expand Down Expand Up @@ -195,9 +196,9 @@
dimensions.getDimensions().forEach((key, val) -> {
try {
emfDimensionSet.addDimension(key, val);
} catch (Exception e) {
// Ignore dimension errors
}

Check failure on line 201 in powertools-metrics/src/main/java/software/amazon/lambda/powertools/metrics/internal/EmfMetricsLogger.java

View workflow job for this annotation

GitHub Actions / pmd_analyse

Avoid empty catch blocks 

Empty Catch Block finds instances where an exception is caught, but nothing is done.
In most circumstances, this swallows an exception which should either be acted on
or reported.

EmptyCatchBlock (Priority: 1, Ruleset: Error Prone)
https://docs.pmd-code.org/pmd-doc-7.14.0/pmd_rules_java_errorprone.html#emptycatchblock
});
coldStartLogger.setDimensions(emfDimensionSet);
}
Expand Down Expand Up @@ -248,9 +249,9 @@
dimensions.getDimensions().forEach((key, val) -> {
try {
emfDimensionSet.addDimension(key, val);
} catch (Exception e) {
// Ignore dimension errors
}

Check failure on line 254 in powertools-metrics/src/main/java/software/amazon/lambda/powertools/metrics/internal/EmfMetricsLogger.java

View workflow job for this annotation

GitHub Actions / pmd_analyse

Avoid empty catch blocks 

Empty Catch Block finds instances where an exception is caught, but nothing is done.
In most circumstances, this swallows an exception which should either be acted on
or reported.

EmptyCatchBlock (Priority: 1, Ruleset: Error Prone)
https://docs.pmd-code.org/pmd-doc-7.14.0/pmd_rules_java_errorprone.html#emptycatchblock
});
singleMetricLogger.setDimensions(emfDimensionSet);
}
Expand Down
10 changes: 6 additions & 4 deletions ...rc/test/java/software/amazon/lambda/powertools/metrics/internal/EmfMetricsLoggerTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -51,7 +51,7 @@ class EmfMetricsLoggerTest {

private Metrics metrics;
private final ObjectMapper objectMapper = new ObjectMapper();
private final PrintStream standardOut = System.out;
private static final PrintStream standardOut = System.out;
private final ByteArrayOutputStream outputStreamCaptor = new ByteArrayOutputStream();

@BeforeEach
Expand Down Expand Up @@ -180,7 +180,7 @@ void shouldAddDimension() throws Exception {
JsonNode dimensions = rootNode.get("_aws").get("CloudWatchMetrics").get(0).get("Dimensions").get(0);
boolean hasDimension = false;
for (JsonNode dimension : dimensions) {
if (dimension.asText().equals("CustomDimension")) {
if ("CustomDimension".equals(dimension.asText())) {
hasDimension = true;
break;
}
Expand Down Expand Up @@ -233,9 +233,9 @@ void shouldAddDimensionSet() throws Exception {
boolean hasDim2 = false;
for (JsonNode dimension : dimensions) {
String dimName = dimension.asText();
if (dimName.equals("Dim1")) {
if ("Dim1".equals(dimName)) {
hasDim1 = true;
} else if (dimName.equals("Dim2")) {
} else if ("Dim2".equals(dimName)) {
hasDim2 = true;
}
}
Expand Down Expand Up @@ -348,6 +348,8 @@ void shouldLogWarningOnEmptyMetrics() throws Exception {
// Read the log file and check for the warning
String logContent = new String(Files.readAllBytes(logFile.toPath()), StandardCharsets.UTF_8);
assertThat(logContent).contains("No metrics were emitted");
// No EMF output should be generated
assertThat(outputStreamCaptor.toString().trim()).isEmpty();
}

@Test
Expand Down
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