… stored together with attributed response time. For example I’d like to see number of mysql calls in addition to MySQL response time. This helps to… see the increased response time for given kind of request. I see response time is coming from MySQL. I check the number of MySQL Queries and it…
Post: Write contentions on the query cache
September 5, 2012 By 5 Comments
… consistent response time (about 160ms). Of course, I wanted to know more about how MySQL … | Status | Duration | +———————-+———-+ | starting | 0.000075 | | checking permissions | 0.000004 | | checking permissions | 0.000004 | | Opening tables | 0….
Post: Percona XtraDB Cluster Feature 2: Multi-Master replication
January 19, 2012 By 22 Comments
…, as it regularly happens with regular MySQL replication if you imprudently write to the… That is response time of COMMIT consist of several parts: Network roundtrip Certification time Local applying …response on particular query, but not on COMMIT. Well, if you follow a good practice, you still check…
Post: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 11, 2013 By 7 Comments
… the overall response time for answering all of the queries in the benchmark. I got some strange results, however, which showed MySQL 5… cache Star Schema Benchmark – Scale Factor 1 – Mysql 5.5 vs 5.6 response times are in seconds (lower is better) Version Buffer….000000 | 0.000000 | 0 | 0 | 0 | 0 | 1 | 1 | | 4 | checking permissions | 0.000015 | 0.000014 | 0.000000 | 0.000000 | 0…
Post: Profiling MySQL Memory Usage With Valgrind Massif
January 9, 2013 By 3 Comments
… indicates which parts of your program are responsible for allocating the heap memory. Firstly, we … After mysqld is properly started (check if you can login with your mysql client), you would execute … running for some time (for example, if you have experienced memory increase over time). Once you’…
Post: Making the impossible: 3 nodes intercontinental replication
January 11, 2012 By 29 Comments
… write queries. Well, you theoretically could create 3 node traditional MySQL ring replication, but this is not what you want to…. Of course you may wonder what is query response time in such environment. We can check it. Simple table: CREATE TABLE t (ID INT) and simple query: INSERT INTO t VALUES (1) Response time on single…
Post: How to use tcpdump on very busy hosts
April 18, 2011 By 17 Comments
… two responses, with a response time of R for each request, and a wait time of W between the requests. If the first response and…, because we must capture the responses from mysqld) #1 has an obvious flaw — if your long-query-time is 1 second, and…=’/tmp’ LOCKFILE=”$self.lockfile” TMPfile=”$self.temp” RESfile=”$self.result” # check lock file if [ -e "$TMP/$LOCKFILE" ]; then echo “$self: lock…
Post: Percona XtraDB Cluster - installation and setup webinar follow up Q&A
October 28, 2012 By 4 Comments
…high throughput despite the response time limitations. Even with parallel replication, the response time limits the number of … asynchronous replication, galera and built-in mysql replication are independent from each other. Q…? Can you swap in Binaries ? A: Check out Jay Janssen’s webinar about the …
Post: When is MIN(DATE) != MIN(DATE) ?
September 4, 2012 By 5 Comments
…time) FROM (SELECT uid, MIN(update_time) AS “update_time” FROM foo WHERE update_time IS NOT NULL AND update_time…27. This is the correct response, not the date from 2012…: Always, always range-check your input! Format-checking is not enough. …. On one hand, it seems like MySQL is using date windowing …
Post: How InnoDB handles REDO logging
February 3, 2011 By 19 Comments
… logged. As the time to log is added to every update it can become an important overhead to your response time. Indeed if InnoDB cannot log at all, your transaction will never complete. Both the MySQL configuration and hardware… process updates is tightly linked to the speed at which check-pointing can occur. In order to insert a new record…
