Unable to open jupyterlab on Google compute notebook instance

I am unable to access Jupyterlab for a couple of days now using the AI Platform > Notebook instances > Open Jupyterlab. I used the + New Instance option and launched a Tensorflow machine but when I click on the Open Jupyterlab button, it only gives me

504. That’s an error.  That’s all we know. 

I have tried downgrading the notebook version and restarting service as suggested here.

sudo pip3 install notebook==5.7.5 sudo service jupyter restart 

This brings me to the familiar Jupyterlab screen but then does not persist (I mean when I log back in to the instance, Jupyterlab still throws up the same error).

Is this a bug in Jupyterlab? Any solution?

Mulitple websites with one instance or with multiple?

I’m not familiar with Magento 2, but would like to know how to deal with multiple shops. I read that Magento supports multiple websites, what sounds interesting. However, I’m wondering when that could or should be used. What are the pros and cons regarding one Magento instance with multiple sites vs one instance per site. When should be used what?

  • Is the multi website feature of Magento only useful if the shops have something in common?
  • If one shop deals with tools and another with shoes, is one instance applicable?
  • How about running 100 shops?
  • How about backend users? One admin, multiple managers (one per shop).
  • Would you recommend the commerce edition or can all be done with the community edition likewise?
  • What is the main intention to have the multi website feature?

Is there a way to get a forensic image of EC2 instance

I currently have an instance on AWS which was compromised and resulted in me losing control. I have shutdown the instance since then, but require a forensic image of the volume so that I can analyze it further.

I have mounted the volume onto another instance to run dd command. when I check the size of the volume it shows 16MB used. What am I doing wrong?

EC2 Instance restarted through AWS Console, started, stopped: site still down. SSH still works

Not sure what else to say, have little experience with EC2, but today I uploaded a new .crt ssl certificate to a website on EC2 ia FileZilla.

Then I logged into the AWS Console, restarted the EC2 Instance, tried starting and stopping the instance.

All says online, running, green dot, but my site is inaccessible, yet SSH still lets me log in with FileZilla.

Anything obvious I can do?

How to force Google Compute Engine ubuntu instance to do fsck?

I have an instance in Google Compute Engine (cloud server) running ubuntu 16.04.

I noticed filesystem corruption on the root filesystem as follows:

==>ls -l data/vocabulary/ ls: cannot access 'data/vocabulary/Makefile': Permission denied ls: cannot access 'data/vocabulary/vocab-count.txt': Permission denied ls: cannot access 'data/vocabulary/vocab-random-access.db': Permission denied ls: cannot access 'data/vocabulary/vocab-list.txt': Permission denied ls: cannot access 'data/vocabulary/vocab.db': Permission denied ls: cannot access 'data/vocabulary/CVS': Permission denied total 0 d????????? ? ? ? ?            ? CVS -????????? ? ? ? ?            ? Makefile -????????? ? ? ? ?            ? vocab-count.txt -????????? ? ? ? ?            ? vocab-list.txt -????????? ? ? ? ?            ? vocab-random-access.db -????????? ? ? ? ?            ? vocab.db 

However, my attempts to “force fsck” and reboot were unsuccessful. I would touch file “/forcefsck” and reboot but fsck just simply would not occur.

I also tried to set the fsck remaining count and that also does not seem to be effective.

What should I do to proceed with fsck?

How can I access the running instance of IIS Express in my Windows Virtual Machine through my Mac OS?

I’m a full stack android developer. I use android studio on my Macbook pro to develop apps and previously used visual studio on my windows VM to develop backend solutions and API’s. This windows virtual machine is installed onto my Macbook.

When I run my solution using IIS Express to test API’s on my virtual machine, is there any way to access the running instance of IIS Express in my virtual machine through my Mac OS? As in, can I consume the API’s I’m running locally in the virtual machine, through let us say postman or an Android emulator, in my Mac OS?

I’d prefer to keep Android Studio in the Mac OS segment of my machine because it performs very well, just runs incredibly smoothly. I’d like to take advantage of that if possible instead of having to install it in the virtual machine. On the other hand, I need access to Microsoft SQL Server Manager, hence the virtual machine.

AWS IAM: Restrict Console Access to only One Instance

I am trying to create an IAM user for the AWS Console with permission to list and perform action on only 1 instance.

So I have a total of 6 Instances and I tried hiding 5 of them via IAM Policies by adding the below policy:

1. First took all the permissions away
2. Added permission to only one instance

    {     "Statement": [         {             "Effect": "Deny",             "Action": "*",             "Resource": "*",             "Condition": {                 "condition": {}             }         },         {             "Effect": "Allow",             "Action": "*",             "Resource": "arn:aws:ec2:us-east-1:123456789012:instance/i-0123456789abcdef",             "Condition": {                 "condition": {}             }         }     ] } 

This works for the 1st part only ie Denying to all Instances.
The 2nd part doesn’t seem to work.

AWS Console with no permission to any instance data

Don’t the permissions work like that? Any help would be appreciated.

Redirect Traffic from one instance to another

I have one AWS EC2 instance (say “VM1”). Now I have two other instances (say C1 and C2). Now, I want to re-direct all traffic that is coming to VM1 to be directed to C1. And, reply/response should also come from C1

PS: What I am basically trying to achieve is that when someone wants to access a file on VM1, it is directed to C1 which has the replica of the same file. (something like a CDN!) . So, the talking happens between the client and C1 and not VM1.

All these VMs (VM1,C1, C2) are ubuntu instances running on AWS.

Please help.

rDNS issue in Cloudflare and AWS ec2 instance

I have installed centos7, whm/cpanel and mailwizz on amazon ec2 instance, managing DNS through cloudflare.com. Everything is fine i have issue with rDNS even i have created PTR records in Route53 and WHM. WHM still shows following issue with PTR in Email Deliverability section.

The system sends “app.mydomain.com”’s outgoing email from the “” IP address. The only PTR value for this IP address must be “app.mydomain.com”. This is the name that this server sends with SMTP’s “HELO” command to send “app.mydomain.com”’s outgoing email.

1 unexpected PTR value exists for this IP address:


To fix this problem, replace all PTR records for “” with the following record at “pdns1.ultradns.net”, “x1.amazonaws.com”, “x2.amazonaws.com”, “x3.amazonaws.org”, and “x4.amazonaws.org”: Suggested “PTR” (PTR) Record PTR
Value: app.mydomain.com.

When i run this command nc -vv localhost 25
Result: localhost [] 25 (smtp) open 220-app.mydomain.com ESMTP Exim 4.91 #1 Sat, 13 Apr 2019 15:48:17 +0000 220-We do not authorize the use of this system to transport unsolicited, 220 and/or bulk e-mail.
any solution?