Package org.apache.hadoop.hbase.http

Class TestProfilerBackendIsolated

java.lang.Object

org.apache.hadoop.hbase.http.TestProfilerBackendIsolated

@Tag("org.apache.hadoop.hbase.testclassification.MiscTests") @Tag("org.apache.hadoop.hbase.testclassification.SmallTests")
public class TestProfilerBackendIsolated
extends Object

Verifies ProfilerBackend.detect(java.lang.String) fallback behaviour when one.profiler.AsyncProfiler is absent from the classpath.

Each test loads ProfilerBackend through a custom ClassLoader that blocks one.profiler.*, simulating a deployment where the async-profiler JAR was never packaged. This is the exact scenario for users who have async-profiler installed as a native binary (ASYNC_PROFILER_HOME) but are not allowed to bundle the JAR.

The split of LibraryBackend into its own file is what makes this possible: ProfilerBackend.class carries no static reference to AsyncProfiler, so the isolated loader can load it without a NoClassDefFoundError.

Field Summary

Fields

Modifier and Type	Field	Description
(package private) Path	tempDir

Constructor Summary

Constructors

Constructor	Description
TestProfilerBackendIsolated()

Method Summary

Modifier and Type	Method	Description
private Method	detectMethod(ClassLoader loader)	Loads ProfilerBackend through the given loader and returns its detect(String) method, made accessible across loader boundaries.
private ClassLoader	isolatedLoader()	Returns a ClassLoader that: - blocks one.profiler.* entirely (simulates absent async-profiler JAR) - reloads org.apache.hadoop.hbase.http.* classes fresh (so LibraryBackend resolves its own imports through this loader and also sees one.profiler.* as absent) - delegates everything else to the parent
void	testDetectPrefersLibraryWhenBothPresent()	Library present AND home set — LibraryBackend must still win (priority check).
void	testDetectReturnsBinaryBackendWhenLibraryAbsentButHomeSet()	User has async-profiler installed as a native binary (ASYNC_PROFILER_HOME set, bin/asprof present) but no JAR on the classpath.
void	testDetectReturnsLibraryBackendWhenLibraryPresent()	When the library IS on the classpath (normal test classpath), detect() must return LibraryBackend regardless of whether a home is set — library takes priority.
void	testDetectReturnsNullWhenLibraryAbsentAndNoHome()	When the library is absent AND no home is set, detect() must return null so that HttpServer registers DisabledServlet instead of crashing.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

tempDir

@TempDir
Path tempDir

Constructor Details

TestProfilerBackendIsolated

public TestProfilerBackendIsolated()

Method Details

testDetectReturnsNullWhenLibraryAbsentAndNoHome

@Test
public void testDetectReturnsNullWhenLibraryAbsentAndNoHome()
                                                     throws Exception

When the library is absent AND no home is set, detect() must return null so that HttpServer registers DisabledServlet instead of crashing.

Throws:

Exception

testDetectReturnsBinaryBackendWhenLibraryAbsentButHomeSet

@Test
public void testDetectReturnsBinaryBackendWhenLibraryAbsentButHomeSet()
                                                               throws Exception

User has async-profiler installed as a native binary (ASYNC_PROFILER_HOME set, bin/asprof present) but no JAR on the classpath. detect() must return BinaryBackend.

Throws:

Exception

testDetectReturnsLibraryBackendWhenLibraryPresent

@Test
public void testDetectReturnsLibraryBackendWhenLibraryPresent()

When the library IS on the classpath (normal test classpath), detect() must return LibraryBackend regardless of whether a home is set — library takes priority.

testDetectPrefersLibraryWhenBothPresent

@Test
public void testDetectPrefersLibraryWhenBothPresent()
                                             throws Exception

Library present AND home set — LibraryBackend must still win (priority check).

Throws:

Exception

isolatedLoader

private ClassLoader isolatedLoader()

Returns a ClassLoader that: - blocks one.profiler.* entirely (simulates absent async-profiler JAR) - reloads org.apache.hadoop.hbase.http.* classes fresh (so LibraryBackend resolves its own imports through this loader and also sees one.profiler.* as absent) - delegates everything else to the parent

detectMethod

private Method detectMethod(ClassLoader loader)
                     throws Exception

Loads ProfilerBackend through the given loader and returns its detect(String) method, made accessible across loader boundaries.

Throws:

Exception