[Gateway] Track only this server's kernels

Author: kevin-bates

notebook/gateway/managers.py

@@ -435,8 +435,13 @@ async def get_kernel(self, kernel_id=None, **kwargs):
                 raise
         else:
             kernel = json_decode(response.body)
-            self._kernels[kernel_id] = kernel
-        self.log.debug("Kernel retrieved: %s" % kernel)
+            # Only update our models if we already know about this kernel
+            if kernel_id in self._kernels:
+                self._kernels[kernel_id] = kernel
+                self.log.debug("Kernel retrieved: %s" % kernel)
+            else:
+                self.log.warning("Kernel '%s' is not managed by this instance." % kernel_id)
+                kernel = None
         return kernel
 
     async def kernel_model(self, kernel_id):
@@ -448,18 +453,19 @@ async def kernel_model(self, kernel_id):
         kernel_id : uuid
             The uuid of the kernel.
         """
-        self.log.debug("RemoteKernelManager.kernel_model: %s", kernel_id)
+        self.log.debug("RemoteKernelManager.kernel_model: %s" % kernel_id)
         model = await self.get_kernel(kernel_id)
         return model
 
     async def list_kernels(self, **kwargs):
         """Get a list of kernels."""
         kernel_url = self._get_kernel_endpoint_url()
-        self.log.debug("Request list kernels: %s", kernel_url)
+        self.log.debug("Request list kernels: %s" % kernel_url)
         response = await gateway_request(kernel_url, method='GET')
         kernels = json_decode(response.body)
-        self._kernels = {x['id']: x for x in kernels}
-        return kernels
+        # Only update our models if we already know about the kernels
+        self._kernels = {x['id']: x for x in kernels if x['id'] in self._kernels}
+        return list(self._kernels.values())
 
     async def shutdown_kernel(self, kernel_id, now=False, restart=False):
         """Shutdown a kernel by its kernel uuid.
@@ -474,9 +480,9 @@ async def shutdown_kernel(self, kernel_id, now=False, restart=False):
             The purpose of this shutdown is to restart the kernel (True)
         """
         kernel_url = self._get_kernel_endpoint_url(kernel_id)
-        self.log.debug("Request shutdown kernel at: %s", kernel_url)
+        self.log.debug("Request shutdown kernel at: %s" % kernel_url)
         response = await gateway_request(kernel_url, method='DELETE')
-        self.log.debug("Shutdown kernel response: %d %s", response.code, response.reason)
+        self.log.debug("Shutdown kernel response: %d %s" % (response.code, response.reason))
         self.remove_kernel(kernel_id)
 
     async def restart_kernel(self, kernel_id, now=False, **kwargs):
@@ -488,9 +494,9 @@ async def restart_kernel(self, kernel_id, now=False, **kwargs):
             The id of the kernel to restart.
         """
         kernel_url = self._get_kernel_endpoint_url(kernel_id) + '/restart'
-        self.log.debug("Request restart kernel at: %s", kernel_url)
+        self.log.debug("Request restart kernel at: %s" % kernel_url)
         response = await gateway_request(kernel_url, method='POST', body=json_encode({}))
-        self.log.debug("Restart kernel response: %d %s", response.code, response.reason)
+        self.log.debug("Restart kernel response: %d %s" % (response.code, response.reason))
 
     async def interrupt_kernel(self, kernel_id, **kwargs):
         """Interrupt a kernel by its kernel uuid.
@@ -501,9 +507,9 @@ async def interrupt_kernel(self, kernel_id, **kwargs):
             The id of the kernel to interrupt.
         """
         kernel_url = self._get_kernel_endpoint_url(kernel_id) + '/interrupt'
-        self.log.debug("Request interrupt kernel at: %s", kernel_url)
+        self.log.debug("Request interrupt kernel at: %s" % kernel_url)
         response = await gateway_request(kernel_url, method='POST', body=json_encode({}))
-        self.log.debug("Interrupt kernel response: %d %s", response.code, response.reason)
+        self.log.debug("Interrupt kernel response: %d %s" % (response.code, response.reason))
 
     def shutdown_all(self, now=False):
         """Shutdown all kernels."""
@@ -512,15 +518,15 @@ def shutdown_all(self, now=False):
         kwargs = {'method': 'DELETE'}
         kwargs = GatewayClient.instance().load_connection_args(**kwargs)
         client = HTTPClient()
-        for kernel_id in self._kernels.keys():
+        for kernel_id in self._kernels:
             kernel_url = self._get_kernel_endpoint_url(kernel_id)
-            self.log.debug("Request delete kernel at: %s", kernel_url)
+            self.log.debug("Request delete kernel at: %s" % kernel_url)
             try:
                 response = client.fetch(kernel_url, **kwargs)
             except HTTPError:
                 pass
             else:
-                self.log.debug("Delete kernel response: %d %s", response.code, response.reason)
+                self.log.debug("Delete kernel response: %d %s" % (response.code, response.reason))
             shutdown_kernels.append(kernel_id)  # avoid changing dict size during iteration
         client.close()
         for kernel_id in shutdown_kernels:
@@ -579,7 +585,7 @@ async def get_all_specs(self):
     async def list_kernel_specs(self):
         """Get a list of kernel specs."""
         kernel_spec_url = self._get_kernelspecs_endpoint_url()
-        self.log.debug("Request list kernel specs at: %s", kernel_spec_url)
+        self.log.debug("Request list kernel specs at: %s" % kernel_spec_url)
         response = await gateway_request(kernel_spec_url, method='GET')
         kernel_specs = json_decode(response.body)
         return kernel_specs

notebook/services/kernels/handlers.py

@@ -54,9 +54,10 @@ def post(self):
 class KernelHandler(APIHandler):
 
     @web.authenticated
+    @gen.coroutine
     def get(self, kernel_id):
         km = self.kernel_manager
-        model = km.kernel_model(kernel_id)
+        model = yield maybe_future(km.kernel_model(kernel_id))
         self.finish(json.dumps(model, default=date_default))
 
     @web.authenticated