28 Matching Annotations
  1. Jan 2020
    1. Indexes are a cornerstone of information retrieval, and the basis for today's modern search engines.
    2. This is known as collapsed forwarding.

      Proxies group a bunch of similar requests, before forwarding the request to app servers.

    3. four of the more important ones are caches, proxies, indexes and load balancers.

      Speeding data retrieval Or reducing latency

    4. benchmark different alternatives, understand how the system will fail, and have a solid plan for when failure happens.

      Managing Failure. Failing gracefully

    5. with the Flickr architecture each shard would need to be updated or searched (or a search service would need to be created to collate that metadata—which is in fact what they do).

      Search service for collating data spread out in shards.

    6. Finally, this separates future concerns, which would make it easier to troubleshoot and scale a problem like slow reads.

      Separation of concern (of components)

    7. Deconstructing a system into a set of complementary services decouples the operation of those pieces from one another. This abstraction helps establish clear relationships between the service, its underlying environment, and the consumers of that service. Creating these clear delineations can help isolate problems, but also allows each piece to scale independently of one another. This sort of service-oriented design for systems is very similar to object-oriented design for programming.

      Service-Oriented-Architecture (SOA)

    8. Cost is the total cost of ownership.

      Cost is total cost of Ownership

    9. the part that makes it scalable is that the resources, or access to those resources, are distributed across multiple servers.

      what is scalability ?

  2. Dec 2019
    1. When building APIs using AWS Lambda, one execution of a Lambda function can serve a single HTTP request
  3. Nov 2019
  4. Oct 2019
    1. Thus the lessonto be learned is that when designing algorithms that operate on trees, it is important to be most efficienton the bottommost levels of the tree (as BuildHeap is) since that is where most of the weight of the treeresides.
    1. Merge is a recursive operation.
    2. In order to maintain this property, each node has a rank, which indidates the length of the path between the node and the right most leaf. For example,

      Rank - https://en.wikipedia.org/wiki/Leftist_tree#S-value

      Rank of a node, is the distance from that node to the nearest leaf in the subtree rooted at that node.

    3. The relationship of left child and right child is not important, so the two child slots in the array for a root can be fully used. (Can we use array to implement a binary search tree?)
    4. unfortunately we cannot have it in pure functional world where mutable array is not recommended.
  5. Sep 2019
    1. When the role attributes take precedence over the default attributes, Chef Infra Client applies those new settings and values during a Chef Infra Client run.
  6. Aug 2019
  7. Jul 2019
    1. Eliminating the fraction of demand that occurs in these spikes eliminates the cost of adding reserve generators, cuts wear and tear and extends the life of equipment, and allows users to cut their energy bills by telling low priority devices to use energy only when it is cheapest.
  8. Jun 2019
    1. On a recent day, three manufacturing firms called the head of a program at KVCC that teaches trade skills asking if it had any students available to fill jobs.
    2. This year, the Promise’s marketing has emphasized vocational college. Administrators hope marginal students will be less likely to drop out of such programs because they are shorter.

      Vocational programs are great for "Builders", who learn by doing stuff than merely reciting study material.

    3. “The challenges that people bring with them to education because of poverty don’t just go away because we say we’re going to pay for college education,”

      Reminds me of "The boy who couldn't read"

    1. Income share agreements could lower costs and improve outcomes by tying loan amounts to objective judgments of how much the student is likely to earn from her degree. Educational quality could also benefit: Investors would presumably advance students money only for schools that were doing a decent job of teaching them. The risks are that some borrowers could end up paying far more under such a scheme than the current plan and that investors might not lend to students they consider too risky.

      The author's counter arguments to Income Share Agreements are not convincing enough for me. They seem abstract and vague.

    2. His administration cut out the middlemen by killing off the Guaranteed Student Loan Program, the one created under Presidents Johnson and Nixon that relied on banks, in favor of a direct loan program, in which money came from the Treasury. But the government’s loose lending policy, with few questions asked, remained in place. The Obama administration also heavily promoted income-based repayment programs, which set borrowers’ monthly payments at 10% of their discretionary income and then forgave a portion of their debt after 20 to 25 years of payments. This severed the link between the value of students’ education and how much they could borrow, providing a huge incentive for schools to raise tuition, since taxpayers would pick up more of the tab. Enrollment in these programs is one big reason that the government’s costs for student loans are exploding.

      Obama revisions to the original student loan program of 1970s started under Johnson and Nixon.

    3. The voucher system, combined with a lack of government oversight, created perverse incentives: Colleges could raise money quickly by admitting academically suspect students while suffering little or no consequences if their students dropped out and defaulted on loans.
    4. In particular, the system gave colleges an incentive to maximize the tuition they extracted from students and the federal taxpayer by boosting fees and enrollment, which meant relaxing admissions standards.

      Reason for inflation in tuition fees -

      1. Higher Enrollment
      2. Relaxing Admission Standards