The Python runtime allows it by pickling the connection. Is there a similar way to share sockets using the Go runtime on classic App Engine with google.golang.org/appengine/socket?
The descriptor isn't exposed in the Go API: https://github.com/golang/appengine/blob/master/socket/socket_classic.go#L152
type Conn struct {
ctx context.Context
desc string
offset int64
prot pb.CreateSocketRequest_SocketProtocol
local, remote *pb.AddressPort
readDeadline, writeDeadline time.Time // optional
}
desc is what you would need on the other side to reconstruct the socket.
It should be possible fork this library on GitHub, change the conn struct to expose the needed desc property, and then change the import to github.com/YOURUSERNAME/appengine/socket instead of appengine/socket.
It's a lot of work so if you can come up with a different way to solve this you're probably better off. Nevertheless it should be possible.
Related
I have a X509_STORE* pointer, my goal is to get its associated X509_STORE_CTX* pointer. May I know how to do this? I cannot get access to where initialize the X509_STORE_CTX*.
probably this is a simple question, but I check the OpenSSL manual API and its related header file again and again, not find any API could do this. Thanks.
A single X509_STORE can be used/shared by an unlimited number of X509_STORE_CTX, but most of the time isn't used/referenced by any, so an API to get "its ... pointer" makes no sense and does not exist.
This (not at all coincidentally) reflects a similar, but inversely named, difference at the SSL module (libssl) level. An SSL_CTX object defines security parameters that can be used by any number of connections each implemented as an SSL object. In the original design, the SSL_CTX owns an X509_STORE representing the truststore -- the set of roots (or other anchors if PARTIAL_CHAIN is used) used to validate peer certs and potentially to build out 'own' chains -- which you can modify using the CTX APIs like SSL_CTX_load_verify_locations or you can get the (automatically created) store with SSL_CTX_get_cert_store and modify it or create your own and install it with SSL_CTX_set_cert_store. OTOH each SSL dynamically creates its own X509_STORE_CTX while validating or sending a cert; no X509_STORE_CTX exists at other times. In 1.0.2 up an SSL by default uses the SSL_CTX store but you can override with SSL_set[01]_{verify,chain}_cert_store.
When you create an X509_STORE_CTX you identify the X509_STORE to use with X509_STORE_CTX_init. When you _free it this use/reference is terminated.
I am developing shared library and subagent for net-snmp. I need to send v3 traps for specific hardware events. I would like to know what value need to be filled in the context value of send_v3trap API.
void send_v3trap(netsnmp_variable_list * vars,const char * context )
Is this context value, same as user defined engine id ? i.e., the one which needs to be configured in snmptrapd.conf as below ?
createUser -e ENGINEID myuser SHA "my authentication pass" AES "my encryption pass"
More on configuring in this link
There is an example source code available for sending
v2traps
By looking at the net-snmp source code, send_v3trap calls internally send_v2trap and eventually,
/* A context name was provided, so copy it and its length to the v2 pdu
* template. */
if (context != NULL)
{
template_v2pdu->contextName = strdup(context);
template_v2pdu->contextNameLen = strlen(context);
}
Answering my own question.
"context" value can be filled with
value returned by "snmpv3_get_engineID"
NULL
As long as, configurations are proper in terms of v3 i.e., trapsess -v3 specified in the host and on the target, engineid of net-snmp is specified, then everything works fine.
Only unclear part still is, if someone is able to send v3 traps without specifying "context", in which scenario would it be useful really !
I'm trying to send a large block of data between applications by sending a control message over DBus from one to the other requesting a Unix file descriptor. I have it so that the client can request this, the server creates a DBus message that includes a UnixFDList, and the client receives a reply message but it doesn't contain anything. On the server side in Vala the DBusConnection object is setup using register_object, unfortunately the Vapi hides the DBusInterfaceVTable parameter that all the C examples use that would let me specify a delegate for method calls. I've tried to use register_object_with_closures instead but I can't seem to get that to work and the Closure object in Vala is woefully undocumented.
It seems to me that I need one of these methods in order to receive the message from the DBusMethodInvocation object that you get from a call to the DBusInterfaceMethodCallFunc delegate, with that you can create a reply message. Is there a way to either specify a closure class that works with register_object_with_closures, or a way to specify a DBusInterfaceVTable object as part of the service data?
I know that one option is to just create the service in C, but I'd rather figure out and understand how this works in Vala.
Vala uses UnixFDList internally for methods that contain a parameter of type GLib.UnixInputStream, GLib.UnixOutputStream, GLib.Socket, or GLib.FileDescriptorBased.
Example:
[DBus(name="eu.tiliado.Nuvola")]
public interface MasterDbusIfce: GLib.Object {
public abstract void get_connection(
string app_id,
string dbus_id,
out GLib.Socket? socket,
out string? token) throws GLib.Error;
}
With Gatling 2, is it possible to repeat with connection re-use? How?
I have the below code, but it appears to open new connection every time. I want to maintain x connections for some time.
val httpProtocol = http
.baseURL("http://mysrv.pvt")
.inferHtmlResources()
val uri1 = "http://mysrv.pvt"
val scn = scenario("Simulation").repeat(50){
pause(2 seconds,20 seconds).
exec(http("request_0")
.get("/s1/serve.html")
)
}
setUp(scn.inject(
atOnceUsers(20000)
).protocols(httpProtocol))
First, your question is not accurate enough.
By default, Gatling has one connection pool per virtual user, so each of them do re-use connections between sequential requests, and can have more than one concurrent connection when dealing with resource fetching, which you do as you enabled inferHtmlResources. This way, virtual users behave as independent browsers.
You can change this behavior and share a common connection pool, see doc. However, you have to make sure this makes sense in your case. Your workload profile will be very different, the toll on the TCP stack on both the client/Gatling and the server/your app will be way less, so make sure that's how your application is being used in production.
What is the full format of the ConnectionString used in StackExchange.Redis?
I have searched but cannot find documentation for it.
If in doubt, use the ConfigurationOptions class (which has properties etc) and ToString() it when you are ready to obtain the configuration-string. However, I suspect you are looking for this
Update. The 'correct' answer links to crazy documentation.
There doesn't seem to be a connect string...
var client = redis.createClient(9000); // Open a port on localhost
var client = redis.createClient('/tmp/redis.sock'); // Open a unix socket
var client = redis.createClient(9000, 'example.com');
This, and options are documented on the README.