SFTP Server in the DMZ or Private Network



UI Response Times


Response-Time Limits
The 3 response-time limits are the same today as when I wrote about them in 1993 (based on 40-year-old research by human factors pioneers):

0.1 seconds gives the feeling of instantaneous response — that is, the outcome feels like it was caused by the user, not the computer. This level of responsiveness is essential to support the feeling of direct manipulation (direct manipulation is one of the key GUI techniques to increase user engagement and control — for more about it, see our User Interface Principles Every Designer Must Know course).
1 second keeps the user’s flow of thought seamless. Users can sense a delay, and thus know the computer is generating the outcome, but they still feel in control of the overall experience and that they’re moving freely rather than waiting on the computer. This degree of responsiveness is needed for good navigation.
10 seconds keeps the user’s attention. From 1–10 seconds, users definitely feel at the mercy of the computer and wish it was faster, but they can handle it. After 10 seconds, they start thinking about other things, making it harder to get their brains back on track once the computer finally does respond.
A 10-second delay will often make users leave a site immediately. And even if they stay, it’s harder for them to understand what’s going on, making it less likely that they’ll succeed in any difficult tasks.

Even a few seconds’ delay is enough to create an unpleasant user experience. Users are no longer in control, and they’re consciously annoyed by having to wait for the computer. Thus, with repeated short delays, users will give up unless they’re extremely committed to completing the task. The result? You can easily lose half your sales (to those less-committed customers) simply because your site is a few seconds too slow for each page.


Kerberos is a protocol for authenticating service requests between trusted hosts across an untrusted network, such as the internet. … The three heads of the Kerberos protocol represent a client, a server and a Key Distribution Center (KDC), which acts as Kerberos’ trusted third-party authentication service.




Handling Millions of Files

Reading / Querying
Commercial Support for Presto: https://www.starburstdata.com/presto-support/

Presto HIVE connector to read files: https://prestodb.io/docs/current/connector/hive.html#supported-file-types

Presto Tutorial: https://www.tutorialspoint.com/apache_presto/index.htm

Reading / Writing
MinIO: https://www.minio.io/
MinIO Distributed

Presto/MinIO/Hive Configuration

Presto Performance and AWS Cost Matrix

Comparison with LLAP/Presto/Tez

A curated list of MinIO