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jerdfelt

145 karma · joined May 29, 2010

[ my public key: https://keybase.io/jerdfelt; my proof: https://keybase.io/jerdfelt/sigs/Y2JqsCyETlsAKZOwKxY1OWl3-P8uzq1eAQsny2RgRMg ]
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jerdfelt··on Porkbun partners with Proton
You don't have to wait until expiry. Transfers generally add 1 year of service (for most TLDs), so unless you're already at the limit, you can transfer everything now.
jerdfelt··on M4 Macs can't virtualise older macOS
Intel has proposed dropping 32-bit and 16-bit support in the future.

https://www.intel.com/content/www/us/en/developer/articles/t...

jerdfelt··on Show HN: Shpool, a Lightweight Tmux Alternative
It is mentioned in the first paragraph of the README:

shpool is a service that enables session persistence by allowing the creation of named shell sessions owned by shpool so that the session is not lost if the connection drops. shpool can be thought of as a lighter weight alternative to tmux or GNU screen.

jerdfelt··on No-op statements syntactically valid only since Python X.Y
Python 2 was even more terse with it's print statement

    print >>sys.stderr, "foo"
jerdfelt··on What every programmer should know about solid-state drives (2014)
Does the ZNS (Zoned Namespaces) spec come close enough?

https://nvmexpress.org/new-nvmetm-specification-defines-zone...

jerdfelt··on The Curse of NixOS
Is there anything that explains the why and how a bit deeper?

As an example, in the video "Packaging a Gem as a Nix derivation", he basically just and copies and pastes another default.nix, changes some strings and mentions he doesn't understand what 'passthrough.updateScript' does, but just changes a string there too.

This doesn't really help me understand Nix.

jerdfelt··on MobileCoin: A New Cryptocurrency from Moxie Marlinspike
I'm not sure if you're trying to imply that Lightning Network is vaporware, but there are currently three implementations that pass the integration tests:

https://github.com/lightningnetwork/lnd https://github.com/ElementsProject/lightning https://github.com/ACINQ/eclair https://cdecker.github.io/lightning-integration/

jerdfelt··on SpaceX raises another $100M
You can get indirect exposure to SpaceX through some Fidelity mutual funds.

http://blog.sfgate.com/pender/2015/03/25/see-which-fidelity-...

jerdfelt··on Greg's Cable Map
The Azores
jerdfelt··on Ask HN: Who wants to be hired? (June 2017)
Location: Redmond, WA

Remote: Yes (have spent the last 6 years working remote)

Willing to relocate: No

Technologies: Python, C, Go, x86 Assembly, Linux, Hypervisors (Xen), Distributed Systems (check my resume for more)

Résumé: http://johannes.erdfelt.com/resume-hn.txt

Email: johannes@erdfelt.com

I've done work from low-level BIOS extensions, to Hypervisor development, to Linux kernel development, to Network Services (DNS, SMTP, DHCP, HTTP, TLS, etc) to high level distributed systems.

I've worked as the first engineer at a startup to large multi-national companies.

I'm generally looking for something in the cloud and/or backend internet services, but I'm open to something new as well.

jerdfelt··on Jeff Bezos’ Annual Letter
Unfortunately, Amazon does not appear to keep different sellers products separate in the warehouse. All it takes is one seller sending counterfeit products to the warehouse for their inventory to be contaminated by counterfeits. This makes "fulfilled by Amazon" more risky in some respects.
jerdfelt··on Ask HN: Is there anything you like about recruiters?
In my experience, do a web search with a unique phrase out of the company or job description. It will often lead to the same job posting directly from the company.
jerdfelt··on Time Is Running Out for NTP
There is NTP the protocol[1], and there is NTP the implementation[2].

While the implementation is popular, there are alternatives. There is also OpenNTPd, chrony and ntimed for instance.

There are also alternatives to the NTP protocol too, such as PTP and SNTP.

[1]https://www.ietf.org/rfc/rfc5905.txt [2]http://www.ntp.org/

jerdfelt··on Zuck’s photos from Facebook’s futuristic Arctic data center
These are farms of cheap Linux boxes.

They go out of their way to design and manufacture their own motherboards and equipment[1] to reduce their capital and operational expenses.

While the motherboard and enclosures are probably custom made, the components inside (CPU, memory, etc) are all "commodity".

[1] http://www.opencompute.org/

jerdfelt··on The Correct Way to Validate Email Addresses
The 63 character limit on domain name labels in RFC 1034/1035 isn't arbitrary, it's a limitation in the way DNS packets are encoded. The upper two bits of the label length are used for compression of labels in DNS packets.

Without protocol changes, DNS cannot support labels longer than 63 bytes.

However, I agree that validating it is unnecessary.

jerdfelt··on Show HN: Twincl – A New Attempt at “Rich Forum”
I agree. All too often people are surprised by it on Reddit. Whenever someone replies with a number followed by a period (eg "42."), it's always converted into "1." Among other problems (escaping of backslashes, etc)
jerdfelt··on Object storage and databases in tandem to create a reliable data storage system
I noticed this blog post is mostly marketing for their minio software, so I went to check it out (I guess the marketing worked).

I wish there was some documentation available. I understand it's an object store, it implements the S3 API and it's open source. It's hard to figure out much more than that.

This is not the first open source object store (Openstack Swift, Ceph, etc) so it's not clear what differentiates this from other options currently available.

Ignoring the competition, what is the design of it? I'm assuming it can scale out by adding more hosts, but the README doesn't mention how to do that. How does it cope with bit rot? Is this designed for read-mostly data or can it deal with a high percentage of writes effeciently?

jerdfelt··on Silicon Valley Asks Mostly for Developers with Degrees
I do not have any degree, relevant or not.

Obviously they were happy with my competency since I was offered a job, they just took the path where they used my lack of degree as a negotiating tactic.

Turns out there are plenty of other places that don't care about degrees and offer more money, so I accepted a job somewhere else. It was an easy decision at the time.

jerdfelt··on Silicon Valley Asks Mostly for Developers with Degrees
This was from the manager I would have been working for. Like any large organization, there are exceptions and he could be the exception rather than the rule. From my perspective, "Google" cared about degrees.
jerdfelt··on Silicon Valley Asks Mostly for Developers with Degrees
I have previously received an offer from Google and was low balled quite a bit. When pressed on this, they pointed to my lack of degree.

So I got a job offer from them without a degree, but they certainly did care.

jerdfelt··on Ask HN: How much do you make at Amazon? Here is how much I make at Amazon
I've always asked for what I want to make and only once have I had a company ask for paystubs to back it up.

That one case was Google (about 8 years ago) and like an idiot I gave them the paystubs (which matched what I asked for). Their offer was 25% less.

jerdfelt··on Docker and Security [pdf]
The number of hypercalls isn't a good indicator of the attack surface area.

As examples:

There is a full x86 instruction decoder which is technically not part of the hypercall interface. x86 instruction encoding is surprisingly complicated. There was a vulnerability in that code: http://xenbits.xen.org/xsa/advisory-123.html

Handling x86 page tables and all of the various feature bits is also surprisingly complicated. This is part of the hypercall interface, but there was also a vulnerability in that code: http://xenbits.xen.org/xsa/advisory-148.html

jerdfelt··on Critical Xen bug in PV memory virtualization code
It depends on the version of Xen they are running. XSA-148 only affects Xen 3.4 and newer. If AWS is running an older version of Xen, they may never have been affected.
jerdfelt··on QEMU heap overflow flaw while processing certain ATAPI commands
XenServer runs their version of qemu under a unique unused uid, in a empty chroot and with a separate network namespace. This is the default behavior under XenServer.
jerdfelt··on What I learned from reading 8,000 recruiting messages
In my experience, recruiters that don't name companies will often cut and paste part of the job description from the company. Often a search with some choice phrases from the job description will find the company the recruiter is trying to hide.
jerdfelt··on Why I don't mock
The Openstack project is a good example of a complex project with complicated testing. Merges are gated on successful test runs of a handful of different tests (unit, integration, etc)

An example of complicated mocking can be seen here:

https://github.com/openstack/nova/blob/master/nova/tests/vir...

In particular, SpawnTestCase.

Disclaimer: While I didn't write this example, I am responsible for some of the other mess

jerdfelt··on When two-factor authentication is not enough
Part of what they do is set up registry locks.

This is different than a registrar lock in that a registrar lock is managed by the registrar (GoDaddy, Tucows, etc) but a registry lock is managed by the registry themselves. It requires personal contact with specific individuals to enable and disable the lock, making attempts to steal domains more difficult (but not impossible since social engineering is still feasible).

I've never used MarkMonitor before, but I did handle the registration for a hugely popular domain at one time. They decided to move to MarkMonitor but in the meantime they requested a registry lock set up on their main domain. This turned out to be very good idea since the registrar at the time was social engineered into changing the credentials for the account (with forged letter head similar to the fastmail.fm attack). The attackers were able to change the nameservers for little used domains but their main domain could not be modified.

jerdfelt··on A successful Git branching model (2010)
I'm not the parent, but I find the nvie.com branching workflow a little complicated.

My experience lies a little bit with the kernel workflow, but heavily with the Openstack workflow, which has large codebases as well.

Both workflows differ from the nvie.com workflow by not needing a 'develop' branch and as a result, needing less merges.

Both Openstack and the Linux kernel use 'master' for development. In the kernel case, changes are reasonably well tested and vetted before they hit 'master' by the use of maintainer branches.

In Openstack, all changes get gated through a variety of unit, functional and integration tests, so they are reasonably well tested as well.

AFAICT, feature and release branches work the same in all three workflows.

I guess both Openstack and the Linux kernel care less about hotfixes since neither run production systems, only their customers do.

In my capacity running a production Openstack system, we apply hotfixes to our release branch and then deploy it from there.

I guess I just really dislike all of the merging that happens in the nvie.com workflow and the extra 'develop' branch as a result. It seems unnecessarily complicated.

jerdfelt··on Designing a Pragmatic RESTful API
Internet Explorer does support SNI since IE7. However Windows XP doesn't even if running IE7 or newer.

That said, we're on our way to a bright SNI filled future, we just have to get over the hump of old versions of Windows and some old mobile devices before it's common enough to be used reliably.

jerdfelt··on This page is anonymous
Only reloadable prepaid cards require SSN. Non-reloadable (Gift) prepaid cards don't require an SSN. Some even allow you to set an address for AVS purposes.
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