Redis – Scan keys with lua script in Node
I have been trying to get all the keys from Redis using scan while also avoiding using count. Problem is, when there are many keys (ex. 1000000) scans SCAN 0 MATCH * are much slower than: KEYS * or SCAN…
Redis – C# LazyCache concurrent dictionary garbage collection
Been having some problems with a web based .Net(C#) application. I'm using the LazyCache library to cache frequent JSON responses (some in & around 80+KB) for users belonging to the same company across user sessions. One of the things we…
Memcached – Why iterating over ndb Datastore query consumes too much memory?
I have a query like: query = HistoryLogs.query() query = query.filter(HistoryLogs.exec_id == exec_id) iter = query.iter() for ent in iter: # write log to file, nothing memory intensive I added logs in the for loop and reading 10K rows increases…
Php versions – Laravel 6 with Nginx, php 7.4 fpm and mysql 8 on docker is slower than Laravel 4 on php 7.1
I have been working on a site built on Laravel 4.2 and on Php 7.1. Recently I have been trying to migrate the site to Laravel 6 with php 7.4 and mysql 8. I setup docker with the following settings.…
Php versions – Finding anagrams from two mysql tables
I am currently trying to implement an algorithm to find anagrams that look like real names. I have a solution that is working but takes too much time for some queries and I am wondering how to improve it. I…
Redis – HMGET and correlation beetwen number of fields and reading performance
Have some question about HMGET performance. Can you explain how number of fields in hash affect reading performance? Example 1. 20000 requests. HMGET with 4 fields. Commands in pipeline. Hash contains 760 fields On test machine it takes about 1500ms.…
Why my Springboot with embbeded tomcat too slow when process first request? – CentOS
Env. OS:macOS Mojave Version 10.14.5(centOS have same problem) Springboot:2.1.6.RELEASE(embedded tomcat 9.0.21),war I am a new player of Spring Boot, which I think is helpful to build my project. Now I have finish my work with it, but a strange phenomenon…
Numpy array computation slower than equivalent Java code – Artificial Intelligence
I am trying to work with large 2D arrays in Python, but it's very slow. For example: start = time.time() result = numpy.empty([5000, 5000]) for i in range(5000): for j in range(5000): result[i, j] = (i * j) % 10…
Mysql slow-query only in script, but not in phpmyadmin. How to solve that?
I have a simple select statement without any join. All it does is checking a date_time and some other flags table has about 45.000 entries. The query is performed within a php script every 5 minutes, to send out an…
MYSQL: Alternative for INNER JOIN with BIG TABLES (It is too slow) – Phpmyadmin
I have two tables (They are bigger with more of 200,000 rows, this is just an example) Table1:temptable id |Chromosome | Start | End | Reference | Alternative | QUAL | MQ ........................................................................ NULL chr1 12334 12335 A TT 10…