A slightly-off Star Wars reference:

"These aren't the droids you're looking for" —Obi-Wan Kenobi Star Wars: Episode IV–A New Hope

I think this statement is misleading. It implies the time is measured from the birth of the queue. It's actually measured since the most recent transmission to the receiver. Source code (Connection.java) says:

• How long to wait, with the receiver not accepting any messages, before kicking the receiver out
• of the distributed system. Ignored if asyncDistributionTimeout is zero.

Make sense. Glad they call this out though!

Is there not a configurable timeout that would have let nodes 2 and 3 form a cluster (with 3 still the leader) and causing node 1 to shut itself down (ostensibly ahead of the fault switch recovering)?

"in parallel to receipt" confuses me. If it said "in parallel to sending the SuspectMembersMessage, the suspicious member initiates a distributed…"

The implication here is that the coordinator can (in general) learn of a network-partition-detected event from other members. This implies that a non-coordinator member notifies the coordinator of a network-partition-detected event.

Seems to me that quorum is lost when the total weight is less-than-or-equal-to 50%. Another way of saying that is quorum requires a majority, and a majority is greater-than 50%.

what's netSearch?

how can Map.put be both a "create" operation and a "modify" operation?

what's the diff between put and Map.put?

woopsie!

the transaction manager can perform a "voluntary commit"? wouldn't that be something only an application could do?

Ah since all data for a replicated region is stored on all members, it follows that a transaction can be run on any member.

For a partitioned region, a transaction would have to run on the member designated as the primary member for buckets containing the data of interest, I suppose.

more here https://docs.oracle.com/cd/E13222_01/wls/docs92/jta/llr.html

Hang on, don't the next two paragraphs directly contradict this statement?

the distinction between "two-phase locking" and "two-phase commit" is not clear

Wait how many phases? There are 5 items on the list after the colon there.

boy immutable object sure would be nice here. Even better, persistent data structures!

I think this applies regardless of the copy-on-read setting. If you need to modify a value (of an entry), you have to modify a copy, and then re-set it via put(k,v) (or some other data-modifying API method)

…should I infer that if I do have copy-on-read set to true, that I can change objects returned from entry access methods?

this makes me think "distributed" is an alias for "replicated". but other doc pages make me think that "distributed" is a superset containing both "replicated" and "partitioned"

?

does this mean that only a client cache, may configure a distributed region that is neither partitioned nor replicated?

the tie-breaker!

I think this is talking about a distributed region here since the second sentence talks about partitioned ones.

i.e. data policy == "normal" right? That data policy says:

• Allows the contents in this cache to differ from other caches.
• Data that this region is interested in is stored in local memory.

If I understand this statement, then we are talking about an update event arriving at a partitioned region (on a peer JVM) or a client region (on a client JVM).

There are then, three kinds of region that might receive this event, I think:

1. primary partitioned region
2. non-primary partitioned region
3. client region (proxy or caching proxy)

Seems to me that the conflict checking would differ in those three cases.

does this mean exactly "partitioned region" here? Or does "non-replicated" mean partitioned regions and client regions?

I think that "receives an update" here means "receives an update event". Contrast that with client code invoking a region update method via the Geode API in a member JVM.

if the region is "non-replicated" then how can the member "(pass) that operation to a member that hosts a replicate"?

this is talking about failure. does the same behavior hold during rebalancing?

Why does Geode burn threads for what is fundamentally an IO-bound process?

there's that word, "system", again. Shouldn't that say "cluster"?

there must be some reason why this seemingly arbitrary, but deterministic algorithm is beneficial. Ah eventual consistency!

there's that need for synchronized clocks again huh

🗝

but wait, this section is about "non-replicated" regions though. I don't get it

…of the entry?

How much clock skew is tolerable?

By "also" is this contrasting regions (distributing updates) to systems distributing updates? It would help if I understood what systems meant above.

Perhaps "system" means "cluster" and the distinction being made here is between serial and parallel replication?

Does "system" mean cluster or member here?

huh?

puzzling

Interesting. So the percentage, not the absolute size, is balanced

Seems like this shouldn't be bound to the concept of a "thread". What if balancing a single region requires multiple threads? What if more than one region can be concurrently rebalanced with a single thread?

This is a nonstandard use of the term "vertical scaling".

This is a mysterious statement. Should it say "client/server" here instead of system-to-system?

Can I define a "monoidal" function in Geode such that the function can run on each partition in parallel, with results from each partition being aggregated up?

"entity groups" is mentioned in the paragraph (twice) and nowhere else on this page and nowhere in the cited paper (Helland). The paper talks about an "entity" which is a think referenced by a key. I think the "groups" here are actually groups of associations (key+entity). The grouping is based on "data affinity".

Why is it available to customers? When would a customer want to use it? When would a customer not want to use it?

Logo > Minecraft? >> Clash of Clans

Rocksmith >> Guitar Hero!

Grain of salt: Kahneman says "I placed too much faith in underpowered studies (about priming research)".

Me too @jon! Good luck to you!

PS it seems like it'd be a very small step from open annotation to allowing somebody to produce a chunk of original content (that is not a reference to anything else). Then we're done :)

:bowtie:

This is a classic.

Surely. Look at what happens to HuffPo…

before:

and after:

Notice that the proxied page is missing the "Iowa Straw Poll" photograph. But perhaps more importantly it's missing the Subaru ad.

As a result, do you think HuffPo would object to the proxied page?

Medium's SPA navigation seems to foil Hypothes.is. I got back to your original Medium post by hitting the back button from a couple levels deep in Medium responses. Notice there are no Hypothes.is comment indicators:

screen shot of Medium article Missing Hypothes.is comment indicator

Revolutionary?

This is an inspiring talk.