majidazimi

30 ms·

91.
by majidazimi 9y ago
Chapter 32: Please (GC pauses the world) rewrite (GC pauses the world) it (GC pauses the world) with (GC pauses the world) C++.
92.
by majidazimi 9y ago
Because GC related issues don't undergo from "problem" state to "solved" state. It is just a never ending stream of issues, that the team need to resolve, specially in a database realm in which metrics are hugely wo
93.
by majidazimi 9y ago
Based on previous research [1], almost every part of a DB is in the hot path. [1] http://15721.courses.cs.cmu.edu/spring2018/papers/02-inmemor...
94.
by majidazimi 9y ago
Well, other than storage engine, the next big part of a database software is the query planner/optimizer which Cassandra doesn't have (due to simple KV nature of it). So there isn't much remaining. In a long term plan, rewrit
95.
by majidazimi 9y ago
> Well, Java has the advantage of being platform (and to a certain degree, runtime) independent What is the benefit of that? Who on earth runs a DB written in Java on windows? Any useful server software will end up using platform native
96.
by majidazimi 9y ago
I don't want to start a war. I'm neither an expert programmer nor a smart person. But isn't it better to put data and validation all together? What if someone forgets to call the validation function? I mean in some complex pr
97.
by majidazimi 9y ago
Except that one could unexpectedly/unintentionally pass "#@%^%#$@#$@#.com" to email function, but Email class works perfectly fine.
98.
by majidazimi 9y ago
We are using it for building aggregate tables from raw table. We insert data into raw table. And triggers propagate running Min/Max/Avg for hourly/daily/monthly tables. After couple of months we truncate our raw tables b
99.
by majidazimi 9y ago
The title should be: We should welcome the advances that are making hospitals less important in US. There is nothing wrong with hospitals in EU.
100.
by majidazimi 9y ago
Call me when they added Triggers, Stored Procedures, Common Table Expressions, Window Functions,...
101.
by majidazimi 9y ago
I can't emphasize this more. Being able to comprehend the system is my first design choice, no matter how the alternatives are great/stable/fast, ... You are going to pay the price some day as long as you don't know how
102.
by majidazimi 9y ago
> A consequence of the "Kubernetes Effect" is that while distributed systems are easy to build and use, a lot of developers lose sight of the fundamental problems which make distributed systems difficult. I would extend this to
103.
by majidazimi 9y ago
A while ago, I answered the same question on Quora[0]. I listed my favorite ones there. And if you are interested into database systems checkout [1]. [0] https://www.quora.com/What-are-some-good-books-on-Distribute... [1]
104.
by majidazimi 9y ago
I still prefer classical scientific books. This book is too much tool driven. I need the actual concept.
105.
by majidazimi 9y ago
Spring 2018 is coming in couple of weeks: http://15721.courses.cs.cmu.edu/spring2018/
106.
by majidazimi 9y ago
> In Kafka and NATS Streaming, reads (and writes) are only served by the leader. Similarly, Amazon Kinesis supports up to only five reads per second per shard (a shard is Kinesis’ equivalent of a partition). Thus, if we have five consume
107.
by majidazimi 9y ago
Basically everyone... All top universities are in the list...
108.
by majidazimi 9y ago
Distributed logs like kafka/pulsar/nats are essentially a blockchain technology in trusted environments. Raft/multi-paxos are already the cheapest communication bound consensus. Theoretically you can't achieve any better
109.
by majidazimi 9y ago
The doc says: > The replica that registers first becomes the new leader. The new leader chooses its LEO as the new HW. Isn't it a better idea to elect a process who has the largest offset? Basically during leader election, a process
110.
by majidazimi 9y ago
Regarding Kafka replication: What if the following scenario happens? 1. Leader replicates to followers 2. Followers get the messages and send ACK to leader 3. Leader gets the confirmation from followers, increments high watermark (HW) and r
111.
by majidazimi 9y ago
Isn't the maximum percentage for singles with no kids in tax category 0, which is around 40%?
112.
by majidazimi 9y ago
Well, as a CS student in a not so highly ranked university, it's not surprising that grads from top CS schools end up in Google, Microsoft Research, etc. They know how stuff work much deeper than others. Of course this is not a general
113.
by majidazimi 9y ago
I use two different controllers in JBOD mode. Each controller manages half of HDDs. Then I build cross controller software RAID 1. That is, I choose two disks from separate controllers to build raid 1. Last but not least, all HDDs are mixed
114.
by majidazimi 9y ago
It's gossip. There is no precise gossip protocol. I've just mentioned one approach. It's not difficult to modify it such that each node gets one message multiple times, to ensure everyone will see the changes. Centrally confi
115.
by majidazimi 9y ago
Always use software RAID. I'd rather loose 30% on efficiency than creating a single point of failure with a random hardware. Software RAID on modern OSes (Linux, FreeBSD, ... ) are pretty darn reliable and fast.
116.
by majidazimi 9y ago
It's not hard. The problem is operation team rarely exercise failures. Configure a test HA cluster in lab, and test it. If it works, push it to production. The production system, should be continuously tested with real failures to see
117.
by majidazimi 9y ago
Zero. Update configuration in a central location. Push an update to configuration manager agent on each node (using a dead simple gossip protocol). The agent wakes up, pulls new configuration, writes it and reloads pgbouncer. Using an aggre
118.
by majidazimi 9y ago
SQL is most sophisticated language ever built by mankind. It is centuries ahead of the second most productive language. Mix Window Functions, Common Table Expressions, Qube/RollUp, Materialized Views, ... and holy smoke... You should t
119.
by majidazimi 9y ago
Considering scientific statistics, which says there are 0.5 to 25 bugs per KLoC in delivered software, we are really lucky that stuff still work... :D
120.
by majidazimi 9y ago
I'm a student assistant at SAP in Germany. Even I (as a part time hourly-paid employee) have a one month notice period.

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