diff --exclude .project --exclude .cproject -Naur tomcat-connectors-1.2.37-src/native/common/jk_ajp_common.c tomcat-connectors-1.2.37-src/native/common/jk_ajp_common.c
--- tomcat-connectors-1.2.37-src/native/common/jk_ajp_common.c	2012-05-28 12:23:40.000000000 +0100
+++ tomcat-connectors-1.2.37-src/native/common/jk_ajp_common.c	2013-02-28 12:31:55.000000000 +0000
@@ -76,6 +76,12 @@
 
 #define UNKNOWN_METHOD (-1)
 
+#define JK_CUSTOM_CHECK_PROTOCOL    "HTTP/1.1"
+#define JK_CUSTOM_CHECK_REMOTE_HOST "127.0.0.1"
+#define JK_CUSTOM_CHECK_REMOTE_PORT "65535"
+#define JK_CUSTOM_CHECK_SERVER_NAME "localhost"
+#define JK_CUSTOM_CHECK_METHOD      "GET"
+
 static int sc_for_req_method(const char *method, size_t len)
 {
     /* Note: the following code was generated by the "shilka" tool from
@@ -862,6 +868,211 @@
     return ret;
 }
 
+/* The below set of functions provide a replacement to ajp_handle_cping_cpong.
+ * (An alternative way to check if the tomcat is ready to receive requests).
+ * Instead of sending a CPING message, send a GET request to a configurable
+ * URL and check the response code. The advantage of this is that we can
+ * check if the app is deployed and ready.
+ *
+ * worker.tomcat_default.custom_check_expected_status=200
+ * worker.tomcat_default.custom_check_uri=/app/emptyfile
+ *
+ * The ping_mode setting to specify when checks happen are still effective.
+ * These checks are enabled by specifying custom_check_uri.
+ */
+
+/* The mod_jk internals don't appear to check these start/read/write callbacks for NULL pointers.
+ * So provide dummy functions. */
+
+static int JK_METHOD check_start_response(jk_ws_service_t *s, int status,
+        const char *reason, const char * const *header_names,
+        const char * const *header_values, unsigned num_of_headers)
+{
+    return JK_TRUE;
+}
+
+static int JK_METHOD check_write(jk_ws_service_t *s, const void *b,
+        unsigned int l)
+{
+    return JK_TRUE;
+}
+
+/* Callback which just tells the engine we read the whole response from AJP. */
+
+static int JK_METHOD check_read(jk_ws_service_t *s, void *b, unsigned len,
+        unsigned *actually_read)
+{
+    *actually_read = len;
+    return JK_TRUE;
+}
+
+/* Create our dummy request in the jk_ws_service_t */
+
+static int ajp_custom_check_init_service(jk_ws_service_t *s, ajp_worker_t *aw)
+{
+    s->start_response = check_start_response;
+    s->read = check_read;
+    s->write = check_write;
+
+    s->req_uri = (char*)aw->custom_check_uri;
+    s->remote_host = s->remote_addr = JK_CUSTOM_CHECK_REMOTE_HOST;
+    s->remote_port = JK_CUSTOM_CHECK_REMOTE_PORT;
+    s->server_name = JK_CUSTOM_CHECK_SERVER_NAME;
+
+    s->protocol = JK_CUSTOM_CHECK_PROTOCOL;
+    s->method = JK_CUSTOM_CHECK_METHOD;
+    s->content_length = 0;
+    s->is_chunked = JK_FALSE;
+
+    return JK_TRUE;
+}
+
+static int ajp_custom_check(ajp_endpoint_t * ae, int timeout, jk_logger_t *l)
+{
+    jk_ws_service_t s; // the dummy request
+    ajp_worker_t *aw; // AJP worker, contains config
+    jk_msg_buf_t *msg; // message buffer, for request and response
+    jk_res_data_t res; // unmarshaled response
+    unsigned char msgType;
+
+    JK_TRACE_ENTER(l);
+
+    jk_log(l, JK_LOG_DEBUG, "Running a mod_jk custom check");
+
+    aw = ae->worker;
+    ae->last_errno = 0;
+
+    /* Pull config from shared mem config to worker. */
+
+    if (aw->sequence != aw->s->h.sequence)
+        jk_ajp_pull(aw, JK_FALSE, l);
+
+    /* Create a message buffer. */
+
+    msg = jk_b_new(&ae->pool);
+
+    if (!msg)
+    {
+        jk_log(l, JK_LOG_ERROR,
+                "Failed allocating AJP message for custom check");
+        JK_TRACE_EXIT(l);
+        return JK_FALSE;
+    }
+
+    /* Set the buffer size to worker config (probably 8K). */
+
+    if (jk_b_set_buffer_size(msg, aw->max_packet_size))
+    {
+        jk_log(l, JK_LOG_ERROR,
+                "Failed allocating AJP message buffer for custom check");
+        JK_TRACE_EXIT(l);
+        return JK_FALSE;
+    }
+
+    /* Clear the buffer and reset its position. */
+
+    jk_b_reset(msg);
+
+    /* Zero all the bytes in the jk_ws_service struct and do some basic init. */
+
+    jk_init_ws_service(&s);
+
+    /* Create our dummy request. */
+
+    ajp_custom_check_init_service(&s, aw);
+
+    if (!ajp_marshal_into_msgb(msg, &s, l, ae))
+    {
+        jk_log(l, JK_LOG_ERROR, "Creating AJP message for custom check failed");
+        JK_TRACE_EXIT(l);
+        return JK_FALSE;
+    }
+
+    jk_log(l, JK_LOG_DEBUG, "sending custom check request...");
+
+    if (ajp_connection_tcp_send_message(ae, msg, l) != JK_TRUE)
+    {
+        jk_log(l, JK_LOG_ERROR, "can't send custom check request");
+        JK_TRACE_EXIT(l);
+        return JK_FALSE;
+    }
+
+    /* wait for reply for timeout milliseconds */
+
+    jk_log(l, JK_LOG_DEBUG, "waiting for custom check response for %d ms...", timeout);
+
+    if (jk_is_input_event(ae->sd, timeout, l) == JK_FALSE)
+    {
+        ae->last_errno = errno;
+        jk_log(l, JK_LOG_INFO, "timeout in custom check response");
+        ajp_abort_endpoint(ae, JK_TRUE, l);
+        JK_TRACE_EXIT(l);
+        return JK_FALSE;
+    }
+
+    /* 1) Unmarshal the SEND_HEADERS message, which contains the HTTP status code we need.
+     * 2) Throw away any SEND_BODY_CHUNK messages.
+     * 3) Stop when we get END_RESPONSE
+     * Anything else is considered an unexpected and an error. */
+
+    while (1)
+    {
+        jk_b_reset(msg);
+        if (ajp_connection_tcp_get_message(ae, msg, l) != JK_TRUE)
+        {
+            jk_log(l, JK_LOG_ERROR, "failed to get responses to custom check");
+            JK_TRACE_EXIT(l);
+            return JK_FALSE;
+        }
+
+        /* We need to consume the first byte so the buffer position is correct for unmarshaling the message. */
+
+        msgType = jk_b_get_byte(msg);
+        if (msgType == JK_AJP13_SEND_HEADERS)
+        {
+            if (!ajp_unmarshal_response(msg, &res, ae, l))
+            {
+                jk_log(l, JK_LOG_ERROR,
+                        "ajp_unmarshal_response on custom check failed");
+                JK_TRACE_EXIT(l);
+                return JK_FALSE;
+            }
+        }
+        else if (msgType == JK_AJP13_SEND_BODY_CHUNK)
+        {
+            jk_log(l, JK_LOG_DEBUG, "got BODY_CHUNK to custom check");
+            continue;
+        }
+        else if (msgType == JK_AJP13_END_RESPONSE)
+        {
+            jk_log(l, JK_LOG_DEBUG, "got END_RESPONSE to custom check");
+            break;
+        }
+        else
+        {
+            jk_log(l, JK_LOG_ERROR, "unexpected response check message type %d",
+                    msgType);
+            JK_TRACE_EXIT(l);
+            return JK_FALSE;
+        }
+    }
+
+    if (res.status == aw->custom_check_expected_code)
+    {
+        jk_log(l, JK_LOG_DEBUG, "mod_jk custom health check succeeded");
+        JK_TRACE_EXIT(l);
+        return JK_TRUE;
+    }
+    else
+    {
+        jk_log(l, JK_LOG_ERROR, "Custom check request got HTTP status %d, expected %d", res.status, aw->custom_check_expected_code);
+    }
+
+    JK_TRACE_EXIT(l);
+
+    return JK_FALSE;
+}
+
 /** Handle the cping/cpong query
  * @param ae       endpoint
  * @param timeout  wait timeout in milliseconds
@@ -879,6 +1090,12 @@
 
     JK_TRACE_ENTER(l);
 
+    /* If a custom check URI and expected code are defined, delegate to the custom check function. */
+    if (ae->worker->custom_check_uri && ae->worker->custom_check_expected_code > 0) {
+        JK_TRACE_EXIT(l);
+        return ajp_custom_check(ae, timeout, l);
+    }
+
     ae->last_errno = 0;
     msg = jk_b_new(&ae->pool);
     if (!msg) {
@@ -1057,6 +1274,9 @@
     aw->retries = aw->s->retries;
     aw->retry_interval = aw->s->retry_interval;
     aw->max_packet_size = aw->s->max_packet_size;
+    aw->custom_check_expected_code = aw->s->custom_check_expected_code;
+    aw->custom_check_uri = aw->s->custom_check_uri;
+
     aw->sequence = aw->s->h.sequence;
     if (aw->addr_sequence != aw->s->addr_sequence) {
         address_change = JK_TRUE;
@@ -1125,6 +1345,9 @@
     aw->s->retries = aw->retries;
     aw->s->retry_interval = aw->retry_interval;
     aw->s->max_packet_size = aw->max_packet_size;
+    aw->s->custom_check_expected_code = aw->custom_check_expected_code;
+    aw->s->custom_check_uri = aw->custom_check_uri;
+
     /* Force squence update on push
      */
      ++aw->s->h.sequence;
@@ -2826,6 +3049,11 @@
             jk_get_worker_prepost_timeout(props, p->name,
                                           AJP_DEF_PREPOST_TIMEOUT);
 
+        p->custom_check_expected_code =
+            jk_get_worker_custom_check_expected_status(props, p->name, JK_HTTP_OK);
+
+        p->custom_check_uri = jk_get_worker_custom_check_uri(props, p->name);
+
         if ((p->ping_mode & AJP_CPING_CONNECT) &&
              p->connect_timeout == AJP_DEF_CONNECT_TIMEOUT)
             p->connect_timeout = p->ping_timeout;
diff --exclude .project --exclude .cproject -Naur tomcat-connectors-1.2.37-src/native/common/jk_ajp_common.h tomcat-connectors-1.2.37-src/native/common/jk_ajp_common.h
--- tomcat-connectors-1.2.37-src/native/common/jk_ajp_common.h	2011-11-09 17:39:01.000000000 +0000
+++ tomcat-connectors-1.2.37-src/native/common/jk_ajp_common.h	2013-02-27 16:33:49.000000000 +0000
@@ -344,6 +344,11 @@
                                * as default for boolean valued connect and prepost timeouts.
                                */
     unsigned int ping_mode;   /* Ping mode flags (which types of cpings should be used) */
+
+    /* Custom check settings. */
+    const char* custom_check_uri;
+    int custom_check_expected_code;
+
     /*
      * Recovery options
      */
diff --exclude .project --exclude .cproject -Naur tomcat-connectors-1.2.37-src/native/common/jk_shm.h tomcat-connectors-1.2.37-src/native/common/jk_shm.h
--- tomcat-connectors-1.2.37-src/native/common/jk_shm.h	2012-05-05 09:50:28.000000000 +0100
+++ tomcat-connectors-1.2.37-src/native/common/jk_shm.h	2013-02-27 16:33:19.000000000 +0000
@@ -90,6 +90,8 @@
     int ping_timeout;
     int reply_timeout;
     int prepost_timeout;
+    const char* custom_check_uri;
+    int custom_check_expected_code;
     unsigned int recovery_opts;
     int retries;
     int retry_interval;
diff --exclude .project --exclude .cproject -Naur tomcat-connectors-1.2.37-src/native/common/jk_util.c tomcat-connectors-1.2.37-src/native/common/jk_util.c
--- tomcat-connectors-1.2.37-src/native/common/jk_util.c	2012-05-15 18:19:03.000000000 +0100
+++ tomcat-connectors-1.2.37-src/native/common/jk_util.c	2013-02-27 14:53:00.000000000 +0000
@@ -56,6 +56,8 @@
 #define RECOVERY_OPTS_OF_WORKER     "recovery_options"
 #define CONNECT_TIMEOUT_OF_WORKER   "connect_timeout"
 #define PREPOST_TIMEOUT_OF_WORKER   "prepost_timeout"
+#define CUSTOM_CHECK_EXPECTED_STATUS_OF_WORKER "custom_check_expected_status"
+#define CUSTOM_CHECK_URI_OF_WORKER            "custom_check_uri"
 #define REPLY_TIMEOUT_OF_WORKER     "reply_timeout"
 #define SOCKET_TIMEOUT_OF_WORKER    "socket_timeout"
 #define SOCKET_CONNECT_TIMEOUT_OF_WORKER "socket_connect_timeout"
@@ -180,6 +182,8 @@
     RECOVERY_OPTS_OF_WORKER,
     CONNECT_TIMEOUT_OF_WORKER,
     PREPOST_TIMEOUT_OF_WORKER,
+    CUSTOM_CHECK_EXPECTED_STATUS_OF_WORKER,
+    CUSTOM_CHECK_URI_OF_WORKER,
     PING_TIMEOUT_OF_WORKER,
     PING_MODE_OF_WORKER,
     REPLY_TIMEOUT_OF_WORKER,
@@ -272,6 +276,8 @@
     RECOVERY_OPTS_OF_WORKER,
     CONNECT_TIMEOUT_OF_WORKER,
     PREPOST_TIMEOUT_OF_WORKER,
+    CUSTOM_CHECK_EXPECTED_STATUS_OF_WORKER,
+    CUSTOM_CHECK_URI_OF_WORKER,
     PING_TIMEOUT_OF_WORKER,
     PING_MODE_OF_WORKER,
     REPLY_TIMEOUT_OF_WORKER,
@@ -1124,6 +1130,31 @@
     return jk_map_get_int(m, buf, def);
 }
 
+int jk_get_worker_custom_check_expected_status(jk_map_t *m, const char *wname, int def)
+{
+    char buf[1024];
+
+    if (!m || !wname) {
+        return -1;
+    }
+
+    MAKE_WORKER_PARAM(CUSTOM_CHECK_EXPECTED_STATUS_OF_WORKER);
+
+    return jk_map_get_int(m, buf, def);
+}
+
+const char *jk_get_worker_custom_check_uri(jk_map_t *m, const char *wname)
+{
+    char buf[1024];
+
+    if (!m || !wname) {
+        return NULL;
+    }
+
+    MAKE_WORKER_PARAM(CUSTOM_CHECK_URI_OF_WORKER);
+    return jk_map_get_string(m, buf, NULL);
+}
+
 int jk_get_worker_ping_timeout(jk_map_t *m, const char *wname, int def)
 {
     char buf[1024];
diff --exclude .project --exclude .cproject -Naur tomcat-connectors-1.2.37-src/native/common/jk_util.h tomcat-connectors-1.2.37-src/native/common/jk_util.h
--- tomcat-connectors-1.2.37-src/native/common/jk_util.h	2012-03-27 09:16:32.000000000 +0100
+++ tomcat-connectors-1.2.37-src/native/common/jk_util.h	2013-02-27 14:53:05.000000000 +0000
@@ -97,6 +97,10 @@
 
 int jk_get_worker_prepost_timeout(jk_map_t *m, const char *wname, int def);
 
+int jk_get_worker_custom_check_expected_status(jk_map_t *m, const char *wname, int def);
+
+const char *jk_get_worker_custom_check_uri(jk_map_t *m, const char *wname);
+
 int jk_get_worker_ping_timeout(jk_map_t *m, const char *wname, int def);
 
 int jk_get_worker_ping_mode(jk_map_t *m, const char *wname, int def);