mjb

8 ms·

1.
by mjb 2mo ago
Among the thugs, Heat, and Dirt are all great reads. Heat is my favorite of them. Highly recommended if you've ever worked in a kitchen, or considered it.
2.
by mjb 3mo ago
You absolutely can run agents on a regular VM. But if you want to build multi-tenant and multi-agent systems with strong security boundaries, then having a VM or MicroVM per agent session (or session with a group of agents) really simplifie
3.
by mjb 3mo ago
AWS AgentCore runtime has been around for about a year: https://docs.aws.amazon.com/bedrock-agentcore/latest/devguid... (spoiler, it's the same underlying technology as the Lambda MicroVMs).
4.
by mjb 3mo ago
A dead comment says: > Of course, this assumes independent events. World Cup, super bowls, etc break these assumptions. Yes, this is very true. The model here works for Poisson arrivals and exponential service time (the M/M), which
5.
by mjb 3mo ago
One explanation would be that more load could mean higher (absolute) variance in queue length, and therefore higher latency especially at higher percentiles. It doesn't work out that way (for reasons that Erlang actually writes about i
6.
by mjb 3mo ago
> What's conspicuously missing is the plot of performance when you do have a well tuned queue in front of the service. As in between the service and the load balancer? There's already an infinite queue in the load balancer. You
7.
by mjb 3mo ago
> With serializable, you need to be a little careful not to have hot rows. Avoid them by sharding commonly written values Unfortunately, serializable isolation requires detecting or preventing read-write conflicts (i.e. one transaction w
8.
by mjb 4mo ago
The 70s, if you want to be pedantic (e.g. Gifford's "Weighted Voting for Replicated Data" or Thomas's "A Majority Consensus Approach to Concurrency Control for Multiple Copy Databases", both from '79).
9.
by mjb 4mo ago
This is cool, and a really fun reminder that "majority" isn't required for quorum systems (it just happens to be the simplest way of thinking about it, and optimal in some senses). Moving from majorities to some other definit
10.
by mjb 5mo ago
Good read. I've always been a little confused about this framing of WSI. The observation that detecting read-write conflicts is sufficient for serializability dates back to at least Kung and Robinson in '83 (IIRC). It is true, tho
11.
The invisible engineering behind Lambda's network(allthingsdistributed.com)
4 points by mjb 5mo ago|0 comments
12.
by mjb 7mo ago
Cool article! > This is why free -h on a Linux box can look alarming. You see almost no “free” memory, but most of it is “available” - and the page cache is using it. And other buffers and stuff too. This is a great thing on bare metal,
13.
by mjb 8mo ago
Indeed. Collecting cameras, and talking about cameras, is a very different hobby from photography. That's OK! Both can be fun. Inspired me to write this blog post: https://brooker.co.za/blog/2023/04/20&#x
14.
by mjb 8mo ago
The haters will hate, but tap guides are great (e.g. https://biggatortools.com/v-tapguide-faqs , but even a block of hard wood with a clearance hole drilled in it works fine). Unless you're tapping something super tough
15.
by mjb 9mo ago
I don't think either is a bad choice, but Aurora has some advantages if you're not a DB expert. Starting with Aurora Serverless: - Aurora storage scales with your needs, meaning that you don't need to worry about running out
16.
by mjb 10mo ago
I spoke about this exact thing at a conference (HPTS’19) a while back. This can work, but introduces modal behaviors into systems that make reasoning about availability very difficult and tends to cause meta stable behaviors and long outage
17.
by mjb 10mo ago
When does AP help? It helps in the case where clients are (a) able to contact a minority partition, and (b) can tolerate eventual consistency, and (c) can’t contact the majority partition. These cases are quite rare in modern internet-conne
18.
by mjb 10mo ago
Practically, the difference in availability for typical internet connected application is very small. Partitions do happen, but in most cases its possible to route user traffic around them, given the paths that traffic tends to take into la
19.
by mjb 10mo ago
Yes, you can do stuff like that. You might enjoy the CRAQ paper by Terrace et al, which does something similar to what you are saying (in a very different setting, chain replication rather than DBs).
20.
by mjb 10mo ago
(Op here) No deadlocks needed! There’s nothing about providing strong consistency (or even strong isolation) that requires deadlocks to be a thing. DSQL, for example, doesn’t have them*. Event sourcing architectures can be great, but they a
21.
by mjb 10mo ago
(OP here). The point of that section, which maybe isn’t obvious enough, is to reflect on how eventually-consistent read replicas limit the options of the database system builder (rather than the application builder). If I’m building the tra
22.
by mjb 10mo ago
(OP here). I don’t love leaking this kind of thing through the API. I think that, for most client/server shaped systems at least, we can offer guarantees like linearizability to all clients with few hard real-world trade-offs. That doe
23.
by mjb 10mo ago
That’s a fair point. To be fair to the academic definitions, “eventually consistent” is a quiescent state in most definitions, and there are more specific ones (like “bounded staleness”, or “monotonic prefix”) that are meaningful to clients
24.
by mjb 10mo ago
Read-your-writes is a client guarantee, that requires stickiness (i.e. a definition of “your”) to be meaningful. It’s not a level of consistency I love, because it raises all kinds of edge-case questions. For example, if I have to reconnect
25.
by mjb 10mo ago
The point is that, in a disaggregated system, the transaction processor has less flexibility about how to route parts of the same transaction (that section is a point about internal implementation details of transaction systems).
26.
by mjb 10mo ago
There is no reason a database can’t be both strongly consistent (linearizable, or equivalent) and available to clients on the majority side of a partition. This is, by far, the common case of real-world partitions in deployments with 3 data
27.
by mjb 11mo ago
This doesn't work as cleanly for SQL-style transactions where there are tons of RW transactions, sadly.
28.
by mjb 11mo ago
Best of all, /dev/null is also serializable (but not strict serializable) under many academic and textbook definitions. Specifically, these definitions require that transactions appear to execute in some serial order, and place
29.
by mjb 11mo ago
That's much better results than mine! I notice a similar 'holographic' effect when coloring titanium a couple weeks back, and experimented with getting them dialed in along the same lines as this video. I didn't have nea
30.
by mjb 11mo ago
I agree. Modern code models tend to do a great job advising in SQL, especially if you include the table definition and EXPLAIN output in the context. Alternatively, I've found that an EXPLAIN MCP tool works well.

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