core/lib/Drupal/Core/Cache/DatabaseBackend.php     |  2 +-
 .../KernelTests/Core/Cache/DatabaseBackendTest.php | 43 ++++++++++++++++++++++
 2 files changed, 44 insertions(+), 1 deletion(-)

diff --git a/core/lib/Drupal/Core/Cache/DatabaseBackend.php b/core/lib/Drupal/Core/Cache/DatabaseBackend.php
index f5d6f89..fac8245 100644
--- a/core/lib/Drupal/Core/Cache/DatabaseBackend.php
+++ b/core/lib/Drupal/Core/Cache/DatabaseBackend.php
@@ -24,7 +24,7 @@ class DatabaseBackend implements CacheBackendInterface {
    *
    * @var int
    */
-  protected static $boundedSizeCount = 1000;
+  public static $boundedSizeCount = 1000;
 
   /**
    * @var string
diff --git a/core/tests/Drupal/KernelTests/Core/Cache/DatabaseBackendTest.php b/core/tests/Drupal/KernelTests/Core/Cache/DatabaseBackendTest.php
index de8bbda..61c3b8d 100644
--- a/core/tests/Drupal/KernelTests/Core/Cache/DatabaseBackendTest.php
+++ b/core/tests/Drupal/KernelTests/Core/Cache/DatabaseBackendTest.php
@@ -48,4 +48,47 @@ public function testSetGet() {
     $this->assertIdentical($cached_value_short, $backend->get($cid_short)->data, "Backend contains the correct value for short, non-ASCII cache id.");
   }
 
+  /**
+   * Tests the row count limiting of cache bin database tables.
+   */
+  public function testGarbageCollection() {
+    $backend = $this->getCacheBackend();
+    $max_rows = DatabaseBackend::$boundedSizeCount;
+
+    $this->assertSame(0, (int) $this->getNumRows());
+
+    // Fill to just the limit.
+    for ($i = 0; $i < $max_rows; $i++) {
+      $backend->set("test$i", $i);
+    }
+    $this->assertSame($max_rows, $this->getNumRows());
+
+    // Garbage collection has no effect.
+    $backend->garbageCollection();
+    $this->assertSame($max_rows, $this->getNumRows());
+
+    // Go one row beyond the limit.
+    $backend->set('test' . ($max_rows + 1), $max_rows + 1);
+    $this->assertSame($max_rows + 1, $this->getNumRows());
+
+    // Garbage collection removes one row: the oldest.
+    $backend->garbageCollection();
+    $this->assertSame($max_rows, $this->getNumRows());
+    $this->assertSame(FALSE, $backend->get('test0'));
+  }
+
+  /**
+   * Gets the number of rows in the test cache bin database table.
+   *
+   * @return int
+   *   The number of rows in the test cache bin database table.
+   */
+  protected function getNumRows() {
+    $table = 'cache_' . $this->testBin;
+    $connection = $this->container->get('database');
+    $query = $connection->select($table);
+    $query->addExpression('COUNT(cid)', 'cid');
+    return (int) $query->execute()->fetchField();
+  }
+
 }