diff --git a/crypto/bio/bio.c b/crypto/bio/bio.c
index 0e3a0d737d..fc6178d61d 100644
--- a/crypto/bio/bio.c
+++ b/crypto/bio/bio.c
@@ -186,6 +186,27 @@ int BIO_read(BIO *bio, void *buf, int len) {
   return ret;
 }
 
+int BIO_read_ex(BIO *bio, void *data, size_t data_len, size_t *read_bytes) {
+  if (bio == NULL || read_bytes == NULL) {
+    OPENSSL_PUT_ERROR(BIO, BIO_R_NULL_PARAMETER);
+    return 0;
+  }
+
+  int read_len = (int)data_len;
+  if (data_len > INT_MAX) {
+    read_len = INT_MAX;
+  }
+
+  int ret = BIO_read(bio, data, read_len);
+  if (ret > 0) {
+    *read_bytes = ret;
+    return 1;
+  } else {
+    *read_bytes = 0;
+    return 0;
+  }
+}
+
 int BIO_gets(BIO *bio, char *buf, int len) {
   if (bio == NULL || bio->method == NULL || bio->method->bgets == NULL) {
     OPENSSL_PUT_ERROR(BIO, BIO_R_UNSUPPORTED_METHOD);
@@ -236,6 +257,31 @@ int BIO_write(BIO *bio, const void *in, int inl) {
   return ret;
 }
 
+int BIO_write_ex(BIO *bio, const void *data, size_t data_len, size_t *written_bytes) {
+  if (bio == NULL) {
+    OPENSSL_PUT_ERROR(BIO, BIO_R_NULL_PARAMETER);
+    return 0;
+  }
+
+  int write_len = (int)data_len;
+  if (data_len > INT_MAX) {
+    write_len = INT_MAX;
+  }
+
+  int ret = BIO_write(bio, data, write_len);
+  if (ret > 0) {
+    if (written_bytes != NULL) {
+      *written_bytes = ret;
+    }
+    return 1;
+  } else {
+    if (written_bytes != NULL) {
+      *written_bytes = 0;
+    }
+    return 0;
+  }
+}
+
 int BIO_write_all(BIO *bio, const void *data, size_t len) {
   const uint8_t *data_u8 = data;
   while (len > 0) {
diff --git a/crypto/bio/bio_test.cc b/crypto/bio/bio_test.cc
index e76f3eb32f..661ef0d4b7 100644
--- a/crypto/bio/bio_test.cc
+++ b/crypto/bio/bio_test.cc
@@ -89,7 +89,7 @@ class OwnedSocket {
 };
 
 struct SockaddrStorage {
-  SockaddrStorage() : storage() , len(sizeof(storage)) {}
+  SockaddrStorage() : storage(), len(sizeof(storage)) {}
 
   int family() const { return storage.ss_family; }
 
@@ -1063,3 +1063,44 @@ TEST(BIOTest, InvokeConnectCallback) {
 }  // namespace
 
 INSTANTIATE_TEST_SUITE_P(All, BIOPairTest, testing::Values(false, true));
+
+TEST(BIOTest, ReadWriteEx) {
+  bssl::UniquePtr<BIO> bio(BIO_new(BIO_s_mem()));
+  ASSERT_TRUE(bio);
+
+  // Reading from an initially empty bio should default to returning a error.
+  // Check that both |BIO_read| and |BIO_read_ex| fail.
+  char buf[32];
+  size_t read = 1;
+  EXPECT_EQ(BIO_read(bio.get(), buf, sizeof(buf)), -1);
+  EXPECT_FALSE(BIO_read_ex(bio.get(), buf, sizeof(buf), &read));
+  EXPECT_EQ(read, (size_t)0);
+
+  // Write and read normally from buffer.
+  size_t written = 1;
+  ASSERT_TRUE(BIO_write_ex(bio.get(), "abcdef", 6, &written));
+  EXPECT_EQ(written, (size_t)6);
+  ASSERT_TRUE(BIO_read_ex(bio.get(), buf, sizeof(buf), &read));
+  EXPECT_EQ(read, (size_t)6);
+  EXPECT_EQ(Bytes(buf, read), Bytes("abcdef"));
+
+  // Test NULL |written_bytes| behavior works.
+  ASSERT_TRUE(BIO_write_ex(bio.get(), "ghilmnop", 8, nullptr));
+  ASSERT_TRUE(BIO_read_ex(bio.get(), buf, sizeof(buf), &read));
+  EXPECT_EQ(read, (size_t)8);
+  EXPECT_EQ(Bytes(buf, read), Bytes("ghilmnop"));
+
+  // Test NULL |read_bytes| behavior fails.
+  ASSERT_TRUE(BIO_write_ex(bio.get(), "ghilmnop", 8, nullptr));
+  ASSERT_FALSE(BIO_read_ex(bio.get(), buf, sizeof(buf), nullptr));
+
+  // Test that |BIO_write/read_ex| align with their non-ex counterparts, when
+  // encountering NULL data. EOF in |BIO_read| is indicated by returning 0.
+  // In |BIO_read_ex| however, EOF returns a failure and sets |read| to 0.
+  EXPECT_FALSE(BIO_write(bio.get(), nullptr, 0));
+  EXPECT_FALSE(BIO_write_ex(bio.get(), nullptr, 0, &written));
+  EXPECT_EQ(written, (size_t)0);
+  EXPECT_EQ(BIO_read(bio.get(), nullptr, 0), 0);
+  EXPECT_FALSE(BIO_read_ex(bio.get(), nullptr, 0, &read));
+  EXPECT_EQ(read, (size_t)0);
+}
diff --git a/include/openssl/bio.h b/include/openssl/bio.h
index 262707f541..8b6b192a0f 100644
--- a/include/openssl/bio.h
+++ b/include/openssl/bio.h
@@ -110,6 +110,15 @@ OPENSSL_EXPORT int BIO_up_ref(BIO *bio);
 // of bytes read, zero on EOF, or a negative number on error.
 OPENSSL_EXPORT int BIO_read(BIO *bio, void *data, int len);
 
+// BIO_read_ex calls |BIO_read| and stores the number of bytes read in
+// |read_bytes|. It returns one on success and zero otherwise.
+//
+// WARNING: Don't use this, use |BIO_read| instead. |BIO_read_ex| returns zero
+// on EOF, which disallows any mechanism to notify the user that an EOF has
+// occurred and renders this API unusable. See openssl/openssl#8208.
+OPENSSL_EXPORT int BIO_read_ex(BIO *bio, void *data, size_t data_len,
+                               size_t *read_bytes);
+
 // BIO_gets reads a line from |bio| and writes at most |size| bytes into |buf|.
 // It returns the number of bytes read or a negative number on error. This
 // function's output always includes a trailing NUL byte, so it will read at
@@ -127,6 +136,12 @@ OPENSSL_EXPORT int BIO_gets(BIO *bio, char *buf, int size);
 // number of bytes written, or a negative number on error.
 OPENSSL_EXPORT int BIO_write(BIO *bio, const void *data, int len);
 
+// BIO_write_ex calls |BIO_write| and stores the number of bytes written in
+// |written_bytes|, unless |written_bytes| is NULL. It returns one on success
+// and zero otherwise.
+OPENSSL_EXPORT int BIO_write_ex(BIO *bio, const void *data, size_t data_len,
+                                size_t *written_bytes);
+
 // BIO_write_all writes |len| bytes from |data| to |bio|, looping as necessary.
 // It returns one if all bytes were successfully written and zero on error.
 OPENSSL_EXPORT int BIO_write_all(BIO *bio, const void *data, size_t len);
@@ -880,7 +895,7 @@ OPENSSL_EXPORT int (*BIO_meth_get_puts(const BIO_METHOD *method)) (BIO *, const
 // does not support secure heaps.
 OPENSSL_EXPORT OPENSSL_DEPRECATED const BIO_METHOD *BIO_s_secmem(void);
 
-  
+
 // General No-op Functions [Deprecated].
 
 // BIO_set_write_buffer_size returns zero.
diff --git a/tests/ci/cdk/cdk/codebuild/github_ci_integration_omnibus.yaml b/tests/ci/cdk/cdk/codebuild/github_ci_integration_omnibus.yaml
index ce8bbc583b..075c1eb183 100644
--- a/tests/ci/cdk/cdk/codebuild/github_ci_integration_omnibus.yaml
+++ b/tests/ci/cdk/cdk/codebuild/github_ci_integration_omnibus.yaml
@@ -102,7 +102,7 @@ batch:
 
     # MySQL build is bloated without any obvious build configurations we can use to speed up the build, so we use a larger instance here.
     - identifier: mysql_integration_x86_64
-      buildspec: tests/ci/codebuild/common/run_simple_target.yml
+      buildspec: tests/ci/codebuild/common/run_nonroot_target.yml
       env:
         type: LINUX_CONTAINER
         privileged-mode: false
@@ -112,7 +112,7 @@ batch:
           AWS_LC_CI_TARGET: "tests/ci/integration/run_mysql_integration.sh"
 
     - identifier: mysql_integration_aarch
-      buildspec: tests/ci/codebuild/common/run_simple_target.yml
+      buildspec: tests/ci/codebuild/common/run_nonroot_target.yml
       env:
         type: ARM_CONTAINER
         privileged-mode: false
diff --git a/tests/ci/integration/mysql_patch/pending_size_t.patch b/tests/ci/integration/mysql_patch/pending_size_t.patch
new file mode 100644
index 0000000000..9fa07d2e3e
--- /dev/null
+++ b/tests/ci/integration/mysql_patch/pending_size_t.patch
@@ -0,0 +1,16 @@
+diff --git a/router/src/openssl/include/tls/details/ssl_operation.h b/router/src/openssl/include/tls/details/ssl_operation.h
+index 44b980d3e4..bdf79319f2 100644
+--- a/router/src/openssl/include/tls/details/ssl_operation.h
++++ b/router/src/openssl/include/tls/details/ssl_operation.h
+@@ -91,7 +91,11 @@ class Operation {
+ 
+     BIO *bio_;
+     SSL *ssl_;
++#if defined (OPENSSL_IS_AWSLC)
++    size_t pending_;
++#else
+     int pending_;
++#endif
+   };
+ };
+ 
diff --git a/tests/ci/integration/mysql_patch/test_wl13075-off.patch b/tests/ci/integration/mysql_patch/test_wl13075-off.patch
index e99a44eb63..338e584fd2 100644
--- a/tests/ci/integration/mysql_patch/test_wl13075-off.patch
+++ b/tests/ci/integration/mysql_patch/test_wl13075-off.patch
@@ -1,8 +1,8 @@
 diff --git a/testclients/mysql_client_test.cc b/testclients/mysql_client_test.cc
-index f1e6744b..26021419 100644
+index 8bc55eda26..a37134221b 100644
 --- a/testclients/mysql_client_test.cc
 +++ b/testclients/mysql_client_test.cc
-@@ -23050,6 +23050,9 @@ static void test_bug32915973() {
+@@ -22324,6 +22324,9 @@ static void test_bug32915973() {
    mysql_stmt_close(stmt);
  }
  
@@ -12,21 +12,21 @@ index f1e6744b..26021419 100644
  static void test_wl13075() {
    int rc;
    myheader("test_wl13075");
-@@ -23182,6 +23185,7 @@ static void test_wl13075() {
+@@ -22456,6 +22459,7 @@ static void test_wl13075() {
      DIE_UNLESS(ret_ses_data == nullptr);
    }
  }
 +#endif
  
- static void finish_with_error(MYSQL *con) {
-   fprintf(stderr, "[%i] %s\n", mysql_errno(con), mysql_error(con));
-@@ -23841,7 +23845,9 @@ static struct my_tests_st my_tests[] = {
+ static void test_bug33535746() {
+   DBUG_TRACE;
+@@ -23770,7 +23774,9 @@ static struct my_tests_st my_tests[] = {
      {"test_bug32892045", test_bug32892045},
      {"test_bug33164347", test_bug33164347},
      {"test_bug32915973", test_bug32915973},
 +#if !defined (OPENSSL_IS_AWSLC)
      {"test_wl13075", test_wl13075},
 +#endif
-     {"test_bug34007830", test_bug34007830},
      {"test_bug33535746", test_bug33535746},
      {"test_server_telemetry_traces", test_server_telemetry_traces},
+     {"test_wl13128", test_wl13128},
diff --git a/tests/ci/integration/run_mysql_integration.sh b/tests/ci/integration/run_mysql_integration.sh
index 012083aee8..bd5f9b7dd5 100755
--- a/tests/ci/integration/run_mysql_integration.sh
+++ b/tests/ci/integration/run_mysql_integration.sh
@@ -6,7 +6,7 @@ set -exu
 
 source tests/ci/common_posix_setup.sh
 
-MYSQL_VERSION_TAG="mysql-8.3.0"
+MYSQL_VERSION_TAG="mysql-cluster-8.4.0"
 # This directory is specific to the docker image used. Use -DDOWNLOAD_BOOST=1 -DWITH_BOOST=<directory>
 # with mySQL to download a compatible boost version locally.
 BOOST_INSTALL_FOLDER=/home/dependencies/boost
@@ -39,7 +39,7 @@ cd ${SCRATCH_FOLDER}
 
 function mysql_patch_reminder() {
   # Check latest MySQL version. MySQL often updates with large changes depending on OpenSSL all at once, so we pin to a specific version.
-  LATEST_MYSQL_VERSION_TAG=`git describe --tags --abbrev=0`
+  LATEST_MYSQL_VERSION_TAG=`git tag --sort=-taggerdate | head -n 1`
   if [[ "${LATEST_MYSQL_VERSION_TAG}" != "${MYSQL_VERSION_TAG}" ]]; then
     aws cloudwatch put-metric-data --namespace AWS-LC --metric-name MySQLVersionMismatch --value 1
   else
@@ -61,17 +61,10 @@ function mysql_run_tests() {
   # to testing AWS-LC functionality.
   # Tests marked with Bug#0001 use stateful session resumption, otherwise known as session caching. It is known that AWS-LC does not
   # currently support this with TLS 1.3.
-  echo "main.mysqlpump_bugs : Bug#0000 Can't create/open a file ~/dump.sql'
-main.restart_server : Bug#0000 mysqld is not managed by supervisor process
+  echo "main.restart_server : Bug#0000 mysqld is not managed by supervisor process
 main.udf_bug35242734 : Bug#0000 mysqld is not managed by supervisor process
 main.file_contents : Bug#0000 Cannot open 'INFO_SRC' in ''
 main.resource_group_thr_prio_unsupported : Bug#0000 Invalid thread priority value -5
-main.dd_upgrade_error : Bug#0000 running mysqld as root
-main.dd_upgrade_error_cs : Bug#0000 running mysqld as root
-main.basedir : Bug#0000 running mysqld as root
-main.lowercase_fs_off : Bug#0000 running mysqld as root
-main.upgrade : Bug#0000 running mysqld as root
-main.mysqld_cmdline_warnings : Bug#0000 running mysqld as root
 main.mysqld_daemon : Bug#0000 failed, error: 256, status: 1, errno: 2.
 main.mysqld_safe : Bug#0000 nonexistent: No such file or directory
 main.grant_user_lock : Bug#0000 Access denied for user root at localhost
@@ -83,7 +76,7 @@ main.client_ssl_data_print  : Bug#0001 AWS-LC does not support Stateful session
 main.ssl_cache : Bug#0001 AWS-LC does not support Stateful session resumption (Session Caching).
 main.ssl_cache_tls13 : Bug#0001 AWS-LC does not support Stateful session resumption (Session Caching).
 "> skiplist
-  ./mtr --suite=main --force --parallel=auto --skip-test-list=${MYSQL_BUILD_FOLDER}/mysql-test/skiplist --retry-failure=3 --retry=3 --report-unstable-tests
+  ./mtr --suite=main --force --parallel=auto --skip-test-list=${MYSQL_BUILD_FOLDER}/mysql-test/skiplist --retry-failure=5 --retry=5 --report-unstable-tests --max-test-fail=30
   popd
 }
 
@@ -128,7 +121,12 @@ mysql_patch_tests
 mysql_patch_error_strings
 
 mysql_build
-mysql_run_tests
+if [ $(uname -p) != "aarch64" ]; then
+  # MySQL's tests use extensive resources. They are slow on ARM and flaky race conditions occur.
+  # TODO: Enable ARM testing when Codebuild releases a larger ARM type (Current Type: 16vCPU, 32GB).
+  mysql_run_tests
+fi
+
 popd
 
 ldd "${MYSQL_BUILD_FOLDER}/lib/libmysqlclient.so" | grep "${AWS_LC_INSTALL_FOLDER}/lib/libcrypto.so" || exit 1