I run my MPJ program using 5 PCs with the same name (DESKTOP-J49PIF5) but it has different IP address. It run successfully in a laboratory. But when I tried to run the same program with the same configuration in a new laboratory (different place), I got "Connection refused" error.
More info that may help.
The same problem happened to my Apache Spark program, but I can solve the problem by adding "--conf “spark.driver.host=<<master_ip>>”" in the configuration. Someone said that the program can not find the driver host so we have to add that extra line in the configuration. Please note that in the previous laboratory I didn't add that line and either my MPJ and Spark program are working.
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Now, my problem is why I got "Connection refused" error in my MPJ program? If the problem is the same as Apache Spark then how can I configure the MPJ? Perhaps by adding master_ip similar to Apache Spark? But I don't know how to do it.
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this error is repeated for 5 PCs.
After struggling for a few days, finally I found the answer. The problem was in the hostnames. Each PC has a different IP address and I can ping them. But, for cluster computing instead of using IP address, it uses the hostname to contact each other so we have to give a unique hostname for every PC. I changed all hostnames and the program is running fine.
Related
I'm using the ProtonVPN Linux CLI client Ubuntu 18.04.
I was previously using the 2.2.6 version, but I wanted to upgrade, which was a huge mistake.
I uninstalled v2.2.6 and followed the instructions for installing v3.7.1 on the ProtonVPN website.
After installation, I was able to create a connection, use the Internet, etc. Everything seemed to work. I enabled the killswitch permanently with $ protonvpn-cli ks --permanent.
Then, I closed my laptop lid. When I re-opened it, I had no Internet connection. I expected this, since that's how the 2.2.6 client worked, and I'm used to having to manually reconnect every time I open my laptop.
I attempted to reconnect to the VPN, but it didn't work the way I expected. $ protonvpn-cli r wouldn't find previous connection data, and $ protonvpn-cli c returned the error
Setting up ProtonVPN
An unknown error has occured. Please ensure that you have internet connectivity.
If the issue persists, please contact support
My wifi connection was fine. If connectivity is the issue, then I assume it must be the killswitch. I disabled the killswitch with $ protonvpn-cli ks --off. My first question is, under v.2.2.6 I did not have to disable the killswitch in order to connect to ProtonVPN itself. Is this changed in v3.7.1?
With the killswitch disabled, $ protonvpn-cli r continues to not find previous connection data, but $ protonvpn-cli c at least makes an attempt at working. However, it's still broken. It takes a minute to load the list of countries. When I select "United States", it seems to freeze while loading the list of servers. I've tried several times, and I've reconnected my wifi. It just won't load servers.
My device now lacks internet connectivity entirely. I've turned off the killswitch, I've closed the terminal I was running protonvpn-cli in, and there are no protonvpn processes active on the machine. The wifi is fine, and other devices are using it to connect to the Internet perfectly well. I've even rebooted the laptop, but it still won't connect to the internet. ProtonVPN has completely wrecked it.
Please help me.
Although I don't think the problem still persists on your side I've struggled with similar problem today. For me the solution found here https://askubuntu.com/questions/1319033/internet-stops-working-after-installing-protonvpn solved all connectivity issues, by simply removing the pvpn-ipv6leak-protection as following:
sudo nmcli connection delete pvpn-ipv6leak-protection
This is from proton's own old web page on how to remove the leftover "always on kill switch" uning command lines in the terminal. It is on the page: "How to install early-access Proton VPN Linux CLI"
located # https://protonvpn.com/support/linux-vpn-tool-early-access/
Disable the kill switch if you have uninstalled the app
The kill switch can be easily disabled from within the official Linux CLI app, but this will not be possible if you have uninstalled the CLI app first without disabling the kill switch. This may result in your system being unable to access the internet. To remove the kill switch after the CLI app has been uninstalled:
a) Identify Proton VPN connection names by running the command:
nmcli connection show --active
This will display a list of all your system’s active connections.
b) Look for any connections with the pvpn- prefix. This usually includes pvpn-killswitch and pvpn-ipv6leak-protection, and may include pvpn-routed-killswitch. Delete all these connections using the following command:
nmcli connection delete [connection name]
For example:
nmcli connection delete pvpn-killswitch
c) Re-run the following command to verify that Proton VPN connections have been deleted:
nmcli connection show --active
If any Proton VPN connections remain, delete them as described above.
Don't know enough about linux to be helpful but have run into the same issue.
Seems to be that proton stuffs with the resolv.conf file.
This link has a fix https://www.reddit.com/r/Ubuntu/comments/cpzaxo/remove_protonvpn_from_ubuntu/
But I can't get it to work as chattr will not allow me to remove the -i permissions.
chattr: Inappropriate ioctl for device while reading flags
Maybe it will work for you
I apologize in advance for how vague this question is. I had a connection string to SQL Server 2012 on a remote server from my work laptop using Visual Studio 2015 and it worked well for connecting to my database to populate asp:dropdownlists etc. on my web app as well as generating reports using SSRS.
That was last week, today I'm getting the error indicated in the title of this post. Below is my connection string minus the specific server name and ip address. Something changed between last Friday and today that this error is popping up.
Provider=SQLOLEDB.1;Data Source=[Server Name];Initial Catalog=[Database Name];Network Address=[Server IP Address]
I admittedly am at a loss as to how to troubleshoot this. I would endlessly appreciate a few leads as to what I can check out, whether there is some sort of log that tracks failed log ins, or some other means of finding out the source of the problem, or what changed.
Thank you so much in advance for helping a brand new programmer.
The problem could be any of the above problems, or a SQL Server configuration issue, or a network problem, or a permissions issue. The first thing I usually try is connecting with SQL Server Management Studio with the same settings. This will give a much more detailed message with specifics of what is failing. In short, all of the numbers in the error message are important and help pinpoint the real problem. You can also use https://msdn.microsoft.com/en-us/library/mt750266.aspx for some other techniques to diagnose/repair the issue.
I'm new to ubuntu and storm , i need to solve this problem
[ERROR] Async loop died!
org.zeromq.ZMQException: Address already in use(0x62)
at org.zeromq.ZMQ$Socket.bind(Native Method)
it appeared in worker log file due to supervisor still hasn't start and by searching found someone wrote that is due to
ephemeral port range was messed
up on the machines
tried to increase /proc/sys/net/ipv4/ip_local_port_range 1024 65000
but not working
This issue is related to already used ports in your system. A port can only be used by a single application. Using lsof -i you can check what application are using which ports. You should spot an conflicting port number. Either terminate this application of change the configuration of Zookeeper or Storm to use a different port.
I have a VMWare Player (Workstation 9 )virtual machine on an Ubuntu 12.10 (13.10 Kernel) host running Ubuntu 12.04 using a bridged connection and set to replicate the physical network connection. Everything usually works properly in a variety of locations. But at one location that I often frequent, the ip address of the virtual machine changes roughly every 10 minutes -rendering the vm entirely useless as it is a postgresql server and thus needs a dedicated local ip. Not only that, but when I copied a database dump into a shared folder, the file ended up getting corrupted.
I can verify that the network caused this problem, as the actual on the vm was not corrupted. I managed to temporarily solve the problem by going into a local modem and setting a DHCP Mac Address. Everything was working and files were not getting corrupted. However, it only lasted temporarily, and another random address was assigned, breaking several running processes on my machine. Between the router/gateway, there is a redundant apple router involved in the network that is likely causing the issue -but I cannot just throw it away or deactivate it, as it is not my network
Furthermore, DHCP leases work just fine for every other machine on the network; so
I believe the root issue is with vmware.
I have no clue what could possibly cause something like this to occur, as IP address assignment is one of those things that normally "just works". I am thinking about just switching to VitualBox, as I have used it in the past and never had a problem (except with properly running Windows 8. However,I have never actually seen any article suggesting VirtualVox over WMWare, as the latter supposedly performs better and has more intuitive shared folder support. Obviously though, any benefit from a shared folder is negated if it just shares corrupt garbage.
So you manually set a MAC address on your VM? In the past, I've seen VM's change MACs quite often; generally only after a reboot or cold start. It shouldn't happen on the fly... You could install Wireshark and grab a few packet captures to see if anything in there points you in the direction of the root cause.
I'm helping to write a program that manages VMs remotely. When I try to connect to a XenServer machine to discover the hypervisor, I get a "Unable to connect: Cannot read CA certificate '/etc/pki/CA/cacert.pem': No such file or directory" error. I've tried creating the cacert.pem file that it's looking for, but that doesn't fix anything. I've read that this certain error isn't accurately showing what's wrong.
This only happens when I use the Java bindings - I can successfully connect to the machine with virsh. I turned on debug mode for libvirt and tried to connect with both the bindings and virsh. The only major difference that I saw is virsh calling several virEvent type methods that libvirt doesn't do. (As I think about it, this may just be libvirt using my custom ConnectAuth class that doesn't prompt for a password)
Using:
libvirt 0.9.12 --with-xenapi
libvirt-java 0.4.7
I can't seem to find anybody else who has had this problem. Any help would be appreciated!
We ended up having to modify the Connect object in libvirt-java. The object was still valid, but somehow an error was being thrown. It's a messy hack, but we just ignore the certain error that is thrown and pass up the Connect object and are able to connect.