similar to: Locks and preventing agaisnt race-conditions with the db

Hi All I am newbie to Rails.. and I am trying to invoke a third party webservice using SOAP::RPC::Driver object. Now I can''t store that in session (it throws TypeError) so the next best thing (on the suggestion by Ola from this mailing list) I am storing it in Class variable or I can store this rpc_driver object in global variable. In brief my concerns are related to race conditions that

I want to be able to display a number of messages, and guarantee that they''re only displayed once. Something like this : def get_new_messages @messages = Message.find(:all, :limit => 5, :conditions => ''new = 1'') @messages.each do |msg| msg.new = 0 msg.save end end However, there''s a race condition in the above code if two users try to access

There are several race conditions where nbdkit exits (calling plugin_cleanup() which unloads the plugin), while the plugin is either in a callback or in plugin.close(). Avoid these by: (1) Taking a shared lock around all plugin callbacks. (2) Taking the same as an exclusive lock in plugin_cleanup. This delays plugin_cleanup until all callbacks have finished. (3) Removing a few unnecessary

On 11/14/2017 11:30 AM, Richard W.M. Jones wrote: > This fixes the race conditions for me, using the test described here: > > https://www.redhat.com/archives/libguestfs/2017-September/msg00226.html Running test-socket-activation in a loop, I've hit other races (some provoked a bit more easily with the code I'm working on), and will be posting some patches where I know the

Hi, Can a dbuf be in DB_CACHED state, db_holds == 0, b_efunc != NULL while its db_buf is put on the eviction list ? From an ASSERT in dbuf_do_evict(), it appears that it can. If it can, I am wondering what is preventing the following race dbuf_hold_impl() db = dbuf_find(dn, level, blkid); ... if (db->db_buf && refcount_is_zero(&db->db_holds)) {

What''s the standard way to prevent race conditions in controllers? Say user has many posts. Post controller has action add_post that receives user id, post controller find()s the user and while he is creating the post entry an administrator deletes that user in a separate session. We cannot assume the database checks foreign key integrity. How do you get that right? -- fxn

Are there any known race conditions with 2.6.18-194.26.1.el5 x86_64 and NFS4? Today a user managed to shut down two identical Intel servers by copying a simple text file via NFS4. Reverting back to 17.1 made the error disappear. On other non-identical hardware the error was not reproducible (so it must be a combination of hardware and this special kernel revision). Anybody interested in a

https://bugzilla.mindrot.org/show_bug.cgi?id=2659 Bug ID: 2659 Summary: Fix race conditions in forwarding tests Product: Portable OpenSSH Version: 7.4p1 Hardware: Other OS: Linux Status: NEW Severity: enhancement Priority: P5 Component: Regression tests Assignee:

I would like to be able to manage different db connections per request. I''ve gotten this working by using establish_connection in a before_filter on all controllers. My concern is whether or not there could be a race condition where two or more overlapping requests might reset the SQL connection. Is there any serialization logic which will prevent this? Must I introduce this logic

The error is caused by the save! method updating an object that another thread (most likely in taskomatic) already updated. In the case of this race condition, we retry saving. However, a proper fix would involve fixing the locking. --- src/db-omatic/db_omatic.rb | 23 ++++++++++++++++++++--- 1 files changed, 20 insertions(+), 3 deletions(-) diff --git a/src/db-omatic/db_omatic.rb

This fixes the race conditions for me, using the test described here: https://www.redhat.com/archives/libguestfs/2017-September/msg00226.html Rich.

After killing an smbd process, or occasionally after a process has died itself, there remains a lock as indicated in an smbstatus output. The process ID tied to the file lock in the db is no longer active, yet the db entry still exists. Is there a way to manually manipulate the file locks db? If not, will any of these entries prohibit another smbd process from handling the file which is indicated

Hi all, I have a multi model form (Project with many tasks) and I want to prevent a task from being saved to the DB if it is empty ie. if there is no i/p for that task from the user. I tried the following class Task < ActiveRecord::Base before_save :check_if_empty ... def check_if_empty self.destroy if description.blank? end but i get this TypeError in ProjectsController#create

Does this model give you functioning mwi? > -----Original Message----- > From: Ray Jackson [mailto:ray@jacksonz.net] > Sent: Friday, January 05, 2007 3:17 PM > To: Asterisk Users Mailing List - Non-Commercial Discussion > Subject: [asterisk-users] Voicemail personalised greetings using > DB/IMAPbackend? > > > Hi all, > > I am attempting to build a horizontally

Sadly, we have discovered another line level interrupt race condition in Xen-4.1. The result was that an outstanding un-eoi''d interrupt at the IO-APIC resulted in the mptsas controller offlining the root filesystem. This is now two separate IO-APIC bugs found recently. 1) Cisco C210 M2 server - EOI Broadcast Suppression, io_apci_ack=old 2) Dell R710 - No EOI Broadcast Suppression,

Rsync people, Tell me if I'm wrong, but rsync seems to have a very serious race condition that would make it risky to transfer files into a directory writable by someone you don't trust if permissions are going to be granted to other people on those files. The rsync receiver creates a half-transferred file with 600 or 700 permissions; then the receiver writes the data and finalizes the

Cpufreq: prevent negative px resident time, add spinlock to avoid race Due to NOW() value may drift between different cpus, we add protection to prevent negative px resident time. Due to both cpufreq logic and xenpm may race accessing cpufreq_statistic_data, we add spinlock to avoid race. Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com> _______________________________________________

We're using rsync to update the tables on our email relays, and very occasionally we get an error in the logs saying that a table has the wrong permissions. This is because of race conditions in finish_transfer() which mean that it does not update files atomically. This makes rsync not entirely safe to use in our situation, where the files being synced are frequently opened for short periods

We use ssh (RedHat 2.5.2p2-5) heavily in non-interactive mode, for managing servers from central controllers, and transferring applications/ data around networks. Very occasionally we've seen the situation where the ssh client and server are both stuck in select, both selecting on only the tcp socket of the connection, and with no timeout. No children of sshd remain (even as zombies), and it

Can anyone offer any advice on this issue? We've tried patching sshd to have a maximum 10 second timeout when calling select() in serverloop.c, and this doesn't appear to have had any ill effects. Thanks, Paul ------- Forwarded Message Date: Tue, 18 Sep 2001 16:49:40 -0700 From: Paul Menage <pmenage at ensim.com> To: mouring at etoh.eviladmin.org cc: Paul Menage