Admin API needs a way of addressing specific clients. Unlike servers, which we
are happy to address by names both because its name reflects its purpose (to
some extent) and we only have two of them (so far), naming clients doesn't make
any sense, since a) each client is an anonymous, i.e. not recognized after a
disconnect followed by a reconnect, b) we can't predict what kind of requests
it's going to send to daemon, and c) the are loads of them comming and going,
so the only viable option is to use an ID which is of a reasonably wide data
type.
Signed-off-by: Erik Skultety <eskultet@redhat.com>
Since threadpool increments the current number of threads according to current
load, i.e. how many jobs are waiting in the queue. The count however, is
constrained by max and min limits of workers. The logic of this new API works
like this:
1) setting the minimum
a) When the limit is increased, depending on the current number of
threads, new threads are possibly spawned if the current number of
threads is less than the new minimum limit
b) Decreasing the minimum limit has no possible effect on the current
number of threads
2) setting the maximum
a) Icreasing the maximum limit has no immediate effect on the current
number of threads, it only allows the threadpool to spawn more
threads when new jobs, that would otherwise end up queued, arrive.
b) Decreasing the maximum limit may affect the current number of
threads, if the current number of threads is less than the new
maximum limit. Since there may be some ongoing time-consuming jobs
that would effectively block this API from killing any threads.
Therefore, this API is asynchronous with best-effort execution,
i.e. the necessary number of workers will be terminated once they
finish their previous job, unless other workers had already
terminated, decreasing the limit to the requested value.
3) setting priority workers
- both increase and decrease in count of these workers have an
immediate impact on the current number of workers, new ones will be
spawned or some of them get terminated respectively.
Signed-off-by: Erik Skultety <eskultet@redhat.com>
New API to retrieve current server workerpool specs. Since it uses typed
parameters, more specs to retrieve can be further included in the pool of
supported ones.
Signed-off-by: Erik Skultety <eskultet@redhat.com>
At first I did not want to do this, but after trying to implement some
newer feaures in the admin API I realized we need that to make our lives
easier. On the other hand they are not saved redundantly and the
virNetServer objects are still kept in a hash table.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
The internal representation of a JSON array counts the items in
size_t. However, for some reason, when asking for the count it's
reported as int. Firstly, we need the function to return a signed
type as it's returning -1 on an error. But, not every system has
integer the same size as size_t. Therefore, lets return ssize_t.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Since its introduction in 2011 (particularly in commit f4324e3292),
the option doesn't work. It just effectively disables all incoming
connections. That's because the client private data that contain the
'keepalive_supported' boolean, are initialized to zeroes so the bool is
false and the only other place where the bool is used is when checking
whether the client supports keepalive. Thus, according to the server,
no client supports keepalive.
Removing this instead of fixing it is better because a) apparently
nobody ever tried it since 2011 (4 years without one month) and b) we
cannot know whether the client supports keepalive until we get a ping or
pong keepalive packet. And that won't happen until after we dispatched
the ConnectOpen call.
Another two reasons would be c) the keepalive_required was tracked on
the server level, but keepalive_supported was in private data of the
client as well as the check that was made in the remote layer, thus
making all other instances of virNetServer miss this feature unless they
all implemented it for themselves and d) we can always add it back in
case there is a request and a use-case for it.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
This function accesses the number of connected clients while properly
locking the server it returns the data about.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
If virNetServerMDNSAddEntry() fails when adding a service to a server,
it doesn't decrease the number of services. Hence access to their
members segfaults (e.g. when free()-ing the sruct).
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Since we don't have syntax-check for this, it has to be checked
manually. Let's hope this is the only place it happened.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
This only affected the servers that re-exec themselves, which is only
virtlockd and it didn't do any mess, so this is mostly a clenaup.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
We have these configuration knobs, like max_clients and
max_anonymous_clients. They limit the number of clients
connected. Whenever the limit is reached, the daemon stops
accepting new ones and resumes if one of the connected clients
disconnects. If that's the case, a debug message is printed into
the logs. And when the daemon starts over to accept new clients
too. However, the problem is the messages have debug priority.
This may be unfortunate, because if the daemon stops accepting
new clients all of a sudden, and users don't have debug logs
enabled they have no idea what's going on. Raise the messages
level to INFO at least.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
A earlier commit changed the global log buffer so that it only
records messages that are explicitly requested via the log
filters setting. This removes the performance burden, and
improves the signal/noise ratio for messages in the global
buffer. At the same time though, it is somewhat pointless, since
all the recorded log messages are already going to be sent to an
explicit log output like syslog, stderr or the journal. The
global log buffer is thus just duplicating this data on stderr
upon crash.
The log_buffer_size config parameter is left in the augeas
lens to prevent breakage for users on upgrade. It is however
completely ignored hereafter.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Any source file which calls the logging APIs now needs
to have a VIR_LOG_INIT("source.name") declaration at
the start of the file. This provides a static variable
of the virLogSource type.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Coverity spotted a use of possibly undefined variable. If a server is
restarting as an result of update, the JSON file that keeps current
value of some variables will not contain the new variables. This is
the case of @max_anonymous_clients too. We are correctly querying if
there's "max_anonymous_clients" in the JSON, however, we are not
setting a sane default if there's none.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
https://bugzilla.redhat.com/show_bug.cgi?id=992980
This config tunable allows users to determine the maximum number of
accepted but yet not authenticated users.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
The counter gets incremented on each unauthenticated client added to the
server and decremented whenever the client authenticates.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Systemd does not forget about the cases, where client service needs to
wait for daemon service to initialize and start accepting new clients.
Setting a dependency in client is not enough as systemd doesn't know
when the daemon has initialized itself and started accepting new
clients. However, it offers a mechanism to solve this. The daemon needs
to call a special systemd function by which the daemon tells "I'm ready
to accept new clients". This is exactly what we need with
libvirtd-guests (client) and libvirtd (daemon). So now, with this
change, libvirt-guests.service is invoked not any sooner than
libvirtd.service calls the systemd notify function.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
There are still two places where we are using 1bit width unsigned
integer to store a boolean. There's no real need for this and these
occurrences can be replaced with 'bool'.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Currently, even if max_client limit is hit, we accept() incoming
connection request, but close it immediately. This has disadvantage of
not using listen() queue. We should accept() only those clients we
know we can serve and let all other wait in the (limited) queue.
Convert the type of loop iterators named 'i', 'j', k',
'ii', 'jj', 'kk', to be 'size_t' instead of 'int' or
'unsigned int', also santizing 'ii', 'jj', 'kk' to use
the normal 'i', 'j', 'k' naming
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
We need to drop the server lock before calling virObjectUnlock(client)
since in case we had the last reference to the client, its dispose
callback would be called and that could possibly try to lock the server
and cause a deadlock. This is exactly what happens when there is only
one QEMU domain running and it is marked to be autodestroyed when the
connection dies. This results in qemuProcessAutoDestroy ->
qemuProcessStop -> virNetServerRemoveShutdownInhibition call sequence,
where the last function locks the server.
Currently all classes must directly inherit from virObject.
This allows for arbitrarily deep hierarchy. There's not much
to this aside from chaining up the 'dispose' handlers from
each class & providing APIs to check types.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
RHEL 6.3 uses dbus-devel-1.2.24, which lacked support for the
DBUS_TYPE_UNIX_FD define (contrast with Fedora 18 using 1.6.8).
But since it is an older dbus, it also lacks support for shutdown
inhibitions as provided by newer systemd.
Compilation failure introduced in commit 31330926.
* src/rpc/virnetserver.c (virNetServerAddShutdownInhibition):
Compile out if dbus is too old.
Use the freedesktop inhibition DBus service to prevent host
shutdown or session logout while any VMs are running.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Currently to deal with auto-shutdown libvirtd must periodically
poll all stateful drivers. Thus sucks because it requires
acquiring both the driver lock and locks on every single virtual
machine. Instead pass in a "inhibit" callback to virStateInitialize
which drivers can invoke whenever they want to inhibit shutdown
due to existance of active VMs.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Add two new APIs virNetServerNewPostExecRestart and
virNetServerPreExecRestart which allow a virNetServerPtr
object to be created from a JSON object and saved to a
JSON object, for the purpose of re-exec'ing a process.
This includes serialization of all registered services
and clients
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Add two new APIs virNetServerClientNewPostExecRestart and
virNetServerClientPreExecRestart which allow a virNetServerClientPtr
object to be created from a JSON object and saved to a
JSON object, for the purpose of re-exec'ing a process.
This includes serialization of the connected socket associated
with the client
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
