Given the CAP theorem I wonder what trade-offs they make and how much visibility they give you into these trade-offs.
In any case this is much better than Amazon's offerings... when they actually ship it. :)
Introducing Cloud Spanner, a Global Database Service
31–40 of 456 posts
Re: Introducing Cloud Spanner, a Global Database Service
#32Doesn't seem possible to use this yet. No client libraries and no samples: https://cloud.google.com/spanner/docs/tutorials Have they documented the wire protocol? I couldn't find it.
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Re: Introducing Cloud Spanner, a Global Database Service
#33The team here at Quizlet did a lot of performance testing on Spanner with one of our MySQL workloads to see if it's an option for us. Here are the test results: https://quizlet.com/blog/quizlet-cloud-spanner
Re: Introducing Cloud Spanner, a Global Database Service
#34> clients can do globally consistent reads across the entire database without locking How is this possible across data centres? Does it send data everywhere at once? Seems too good to be true of course but if it works and scales it might be worthwhile just not having to worry about your database scaling? Still I don't believe it ;-) EDIT: further info... > Spanner mitigates this by having each member be a Paxos group…
> In terms of CAP, Spanner claims to be both consistent and highly available despite operating over a wide area, which many find surprising or even unlikely. The claim thus merits some discussion. Does this mean that Spanner is a CA system as defined by CAP? The short answer is “no” technically, but “yes” in effect and its users can and do assume CA.
The purist answer is “no” because partitions can happen and in fact have happened at Google, and during some partitions, Spanner chooses C and forfeits A. It is technically a CP system.
Re: Introducing Cloud Spanner, a Global Database Service
#35Doesn't seem possible to use this yet. No client libraries and no samples: https://cloud.google.com/spanner/docs/tutorials Have they documented the wire protocol? I couldn't find it.
I work on Cloud Spanner and client libraries are rolling out right now, but API definitions are available.
RPC: https://cloud.google.com/spanner/docs/reference/rpc/ Rest: https://cloud.google.com/spanner/docs/reference/rest/
Re: Introducing Cloud Spanner, a Global Database Service
#36> Today, we’re excited to announce the public beta for Cloud Spanner, a globally distributed relational database service that lets customers have their cake and eat it too: ACID transactions and SQL semantics, without giving up horizontal scaling and high availability. This is a bold claim. What do they know about the CAP theorem that I don't? Separately, (emphasis mine): > If you have a MySQL or PostgreSQL system th…
Theoretically it means they are giving up on being Partition Tolerant. There was a popular post a while ago about how the P can't be sacrificed. Because if it is... everything else will fail. Being Google they are probably prideful enough to think their servers could never have an outage. Which yes, I agree with you, that is a very scary claim.
This is thoroughly wrong. Cloud Spanner sacrifices the "A", not the "P." The cool thing being accomplished here is that the sacrifice to the A is greatly reduced (five or more 9s). There are several documents on the subject linked right off that page and elsewhere in these same comments, like this one: https://cloud.google.com/spanner/docs/whitepapers/SpannerAnd...
Re: Introducing Cloud Spanner, a Global Database Service
#37The sql syntax reference looks similar to that of Postgres' syntax reference.
Re: Introducing Cloud Spanner, a Global Database Service
#38> Unlike most wide-area networks, and especially the public internet, Google controls the entire network and thus can ensure redundancy of hardware and paths, and can also control upgrades and operations in general I know this is a single system, but I'll still say it. This seems like another step in a scary trend for our internet.
Why is it a scary trend that Google has made their part of the internet more resilient?
Re: Introducing Cloud Spanner, a Global Database Service
#39The team here at Quizlet did a lot of performance testing on Spanner with one of our MySQL workloads to see if it's an option for us. Here are the test results: https://quizlet.com/blog/quizlet-cloud-spanner
What's the SQL and wire compatibility level? MySQL?
EDIT: Found quite a bit of my answers in your linked article:
> Cloud Spanner uses a SQL dialect which matches the ANSI SQL:2011 standard with some extensions for Spanner-specific features. This is a SQL standard simpler than that used in non-distributed databases such as vanilla MySQL, but still supports the relational model (e.g. JOINs). It includes data-definition language statements like CREATE TABLE. Spanner supports 7 data types: bool, int64, float64, string, bytes, date, timestamp[20].
> Cloud Spanner doesn't, however, support data manipulation language (DML) statements. DML includes SQL queries like INSERT and UPDATE. Instead, Spanner's interface definition includes RPCs for mutating rows given their primary key[21]. This is a bit annoying. You would expect a fully-featured SQL database to include DML statements. Even if you don't use DML in your application you'll almost certainly want them for one-off queries you run in a query console.
> Though Cloud Spanner supports a smaller set of SQL than many other relational databases, its dialect is well-documented and fits our use case well. Our requirements for a MySQL replacement are that it supports secondary indices and common SQL aggregations, such as the GROUP BY clause. We've eliminated most of the joins we do, so we haven't tested Cloud Spanner's join performance.
This seems like it'd prevent any kind of easy switch over to Spanner.
Re: Introducing Cloud Spanner, a Global Database Service
#40I wonder why they charge a minimum of $0.90 per node-hour when they offer VMs for as little as $0.008/hr. This is hugely useful even for single-person startups, so why charge a minimum of ~$8,000 per year?
Because it's highly innovative. Cost != value.