ProxySQL Tutorial. With a GPL license! High Performance & High Availability Proxy for MySQL. Santa Clara, California April 23th 25th, 2018

Transcription

1 ProxySQL Tutorial High Performance & High Availability Proxy for MySQL With a GPL license! Santa Clara, California April 23th 25th, 2018

2 Who we are René Cannaò ProxySQL Founder Derek Downey Director of OSDB, Pythian 2

3 Agenda What is ProxySQL? Features Fundamentals What is new? Internals Admin Clustering Rules Mirroring Failover New protocols GTID casual reads 3

4 Other sessions Consistent Reads Using ProxySQL and GTID Tuesday April 24, Automatic Failovers with Kubernetes using Orchestrator, ProxySQL and Zookeeper Tuesday April 24, 4

5 Overview of ProxySQL

6 What is ProxySQL The MySQL data stargate 6

7 Main motivations empower the DBAs improve operation understand and improve performance create a proxy layer to shield the database High performance and High Availability 7

8 ProxySQL Features Some of the most interesting features: on-the-fly rewrite of queries caching reads outside the database server connection pooling and multiplexing complex query routing and read/write split load balancing real time statistics monitoring Data masking Multiple instances on same ports

9 ProxySQL Features (2) Some of the most interesting features: High Availability and Scalability seamless failover firewall query throttling query timeout query mirroring runtime reconfiguration Scheduler Support for Galera/PXC and Group Replication

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11 What s new in ProxySQL Native Support for Group Replication Multiple regex engines Better performance Support for millions of users Support for tens of thousands of database servers Better queries control

12 What s new in ProxySQL Native ProxySQL Clustering Solution Support for ClickHouse as a backend SQLite network Support for millions of shards

13 What s new in ProxySQL 2.0 (dev) all in 1.4.x plus: Support for Aurora SSL support for frontend SSLv1.2 Native Support for Galera Causal reads using GTID Multi-threaded connections reset

14 Hostgroups and Query Routing All backends are grouped into hostgroups Hostgroups have logical functionalities

15 Hostgroups example #1 HostGroup0 (HG0): Write masters HostGroup1( HG1): Read slaves Read/Write split

16 Hostgroups example #2 HG0: main write masters HG1: main read slaves HG2: reporting slaves HG3: ad-hoc queries slaves HG4: data warehouse write masters HG5: data warehouse read slaves HG6: remote site servers HG7: test servers HG8 : mirror for traffic on HG0 HG9 : mirror for traffic on HG1

17 Basic design HG0 APP1 HG1 APP2 ProxySQL HG2 APP3

18 Basic design HG0 APP APP HG1 ProxySQL HG2 Very low latency using Unix Domain Socket (?)

19 One ProxySQL per host

20 Silos approach

21 Clustered ProxySQL Architecture APP APP APP APP PROXYSQL PROXYSQL PROXYSQL PROXYSQL Clustered Proxy Layer PROXYSQL PROXYSQL PROXYSQL DBMANAGER DB DB DB DB DB DB

22 Clustered ProxySQL at scale Tested with: 8 app servers with 3k clients connections each (24k total) 4 middle layer proxysqls processing 4k connections each from local proxysqls (16k total) 256 backends/shard (meaning 256 routing rules) processing 600 connections each (150k total) Single ProxySQL was tested with up to 950k connections At today, ProxySQL is able to process up to 750k QPS

23 ProxySQL Internals

24 ProxySQL Modules in 1.3.x ProxySQL APP1 Queries cache HG0 Monitoring APP2 Users Auth APP3 Thread #1 HG1 Connection Pool Query Processor Hostgroup Manager Thread #2 Thread #3 Admin

25 ProxySQL Modules in 1.4.x ProxySQL APP1 Monitoring ClickHouse Server Admin SQLite3 Server Query Processor Thread #3 idles Thread #3 Thread #2 idles Thread #2 Users Auth Thread #1 idles Queries cache APP3 Cluster ClickHouse Auth Thread #1 APP2 HG0 Purge Thread Connection Pool Hostgroup Manager HG1

26 Queries Processor Based on Queries Rules Defines what to cache Defines the hostgroup target Timeout/delay Firewall Mirroring Rewrite queries

27 Queries rules Complex rules to match incoming traffic: regex on query regex on digest text username schemaname Source IP address Bind IP address/port digest Rules can be chained

28 Queries Cache and Rewrite Caching on the wire Internal key/value storage In memory only Pattern based Expired by timeout Rewrite on the wire Regex match/replace on query on digest text Optionally cached or mirrored

29 Users Authentication Credentials stored in the proxy User login always possible (even without backends) Max connections Login credentials are encrypted Extremely scalable, up to millions of users:

30 Hostgroups Manager Management of servers Track servers status Tightly integrated with the connections pool

31 Connections Pool Reduced the overhead of creating new connections, and are recycled when not in use One to many connections Multiplexing & maximum connections Auto-reconnect and automatic re-execution of queries Failover management

32 Purge Thread Unsafe connections are reset instead of being dropped Drastically reduce the need to establish new connections In ProxySQL 2.0 : each worker thread perform most of the reset

33 Auto-reconnect and re-execution Automatic detection of failures Graceful handling Auto-reconnect when possible Pause until a backend becomes available Re-execution of queries

34 Multiplexing Reduce the number of connections against mysqld (configurable) Many clients connections (tens of thousands) can use few backend connections (few hundreds) Tracks connection status (transactions, user variables, temporary tables, etc) Order by waiting time

35 Multiplexing (see it in web UI)

36 Multiplexing (see it in web)

37 More metrics on web UI

38 More metrics on web UI

39 More metrics on web UI

40 Monitoring Module It monitors backends and collects metrics Monitors replication lag and shun hosts Monitors read_only (and super_read_only and innodb_read_only in 2.0) variables (replication hostgroups) Ping and terminates unresponsive nodes

41 Monitoring Module Built in support for asynchronous replication: second behind master and pt-heartbeat Support for any type of clustering solution via external scripts (Galera/PXC, and any heterogeneous replication setup) In ProxySQL 1.4.0, support for Group Replication In ProxySQL 2.0, support for Galera

42 Admin Module

43 Admin Interface Allows runtime configuration Exports internal statuses It uses MySQL protocol Configuration possible from any client/tool using MySQL API Covered during the tutorial

44 Admin Interface Disk Memory Runtime Runtime Memory Config Disk

45 Try it! Source code on GitHub: Forum: Tutorials on:

46 Demo Environment

47 Demo Code on GitHub: Some hosts provided: Username: plsc Passwords: proxysql 47

48 ProxySQL Cluster

49 ProxySQL Cluster New in experimental (not fully completed, subject to change) Support for MySQL Query Rules, MySQL Users, MySQL Servers and ProxySQL Servers A group of instances constantly check each other for changes in configuration A configuration change applied in a proxy is pulled by the other proxies Allow to keep multiple ProxySQL instances with the same configuration(s)

50 ProxySQL Cluster

51 ProxySQL Cluster Conflict resolution is timestamp based No order Last win No quorum (in the roadmap) Highly scalable: Core nodes vs satellite nodes

52 ProxySQL Cluster - Config mysql> SET admin-cluster_username='radmin'; mysql> SET admin-cluster_password='radmin'; mysql> LOAD ADMIN VARIABLES TO RUNTIME; mysql> SAVE ADMIN VARIABLES TO DISK; mysql> INSERT INTO proxysql_servers (hostname) VALUES ('proxysql1'),('proxysql2'),('proxysql3'); mysql> LOAD PROXYSQL SERVERS TO RUNTIME; mysql> SAVE PROXYSQL SERVERS TO DISK; mysql> SHOW VARIABLES LIKE 'admin-cluster%'; Variable_name Value admin-cluster_username radmin admin-cluster_password radmin admin-cluster_check_interval_ms 1000 admin-cluster_check_status_frequency 10 admin-cluster_mysql_query_rules_diffs_before_sync 3 admin-cluster_mysql_servers_diffs_before_sync 3 admin-cluster_mysql_users_diffs_before_sync 3 admin-cluster_proxysql_servers_diffs_before_sync 3 admin-cluster_mysql_query_rules_save_to_disk true admin-cluster_mysql_servers_save_to_disk true admin-cluster_mysql_users_save_to_disk true admin-cluster_proxysql_servers_save_to_disk true rows in set (0.00 sec) 52

53 ProxySQL Cluster - Monitoring Stats_proxysql_servers_checksums Stats_proxysql_servers_metrics 53

54 ProxySQL Cluster DEMO

55 MySQL Query rules

56 Query rewriting overview Sql-aware Regex-based flexible 56

57 Query rewriting examples read/write splitting Data masking Sharding 57

58 Query rewriting flow 58

59 Match Related Tables mysql_query_rules username schemaname flagin/out client_addr proxy_addr proxy_port digest match_digest match_pattern negate_match_pattern mysql_users active fast_forward(bypass)

60 Action related fields flagout replace_pattern destination_hostgroup cache_ttl timeout retries delay mirror_flagout mirror_hostgroup OK_msg error_msg log multiplex apply active

61 3 layers for ProxySQL tables Disk Memory Runtime Runtime Memory Config Disk

62 Precautions Confirm the query hits with stats_mysql_query_rules double check rules and rewrite results hold off on writing rules to disk until you're sure they are working as expected have a rollback plan load from disk, then load from memory to runtime test select query rules and rewrites on a slaves first test mutable rules on a mirror or other throw away db.

63 Example - Simple R/W mysql> SELECT username, default_hostgroup FROM mysql_users\g *************************** 1. row *************************** username: root default_hostgroup: 0 1 row in set (0.00 sec) mysql> SELECT match_digest, destination_hostgroup FROM mysql_query_rules\g *************************** 1. row *************************** match_digest: ^SELECT.*FOR UPDATE destination_hostgroup: 0 *************************** 2. row *************************** match_digest: ^SELECT destination_hostgroup: 1 2 rows in set (0.00 sec) 63

64 Query Rewriting with ProxySQL DEMO Click to add text

65 Mirroring with ProxySQL Click to add text

66 What is mirroring? 66

67 What is mirroring? 67

68 Why mirror queries? Validate performance on a different server using different hostgroups. Validate performance of query rewrite or schema change Pre-fetch slave replication (Replication Booster) 68

69 How to mirror mysql>show CREATE TABLE mysql_query_rules\g *********************** 1. row ************************ table: mysql_query_rules Create Table: CREATE TABLE mysql_query_rules ( rule_id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, active INT CHECK (active IN (0,1)) NOT NULL DEFAULT 0, username VARCHAR, schemaname VARCHAR, flagin INT NOT NULL DEFAULT 0, *snip* mirror_flagout INT UNSIGNED, mirror_hostgroup INT UNSIGNED, error_msg VARCHAR, *snip*) 69

70 Mirroring flow 70

71 Mirroring - example #1 mysql> SELECT username, destination_hostgroup, mirror_hostgroup, mirror_flagout FROM mysql_query_rules WHERE username='plam_mirror'\g ****************** 1. row ********************** username: pl_mirror destination_hostgroup: 3 mirror_hostgroup: 4 mirror_flagout: NULL 71

72 Mirroring - example #2 72

73 Mirroring Demo Click to add text

74 Mirroring caveats Can be dropped: mysql-mirror_max_concurrency, mysql-mirror_max_queue_length Can be executed out of order No error handling of failed queries 74

75 Failover with ProxySQL

76 Failover highlights improve failover time as perceived by the application prevent errors sent to the application perform transparent database failovers: gracefully redirecting traffic without the application knowing existing applications do not have to be rewritten to autoreconnect since connections are not lost from failovers 76

77 Failover scenario - without ProxySQL 77

78 Failover scenario - without ProxySQL 78

79 Failover scenario - with ProxySQL 79

80 Failover scenario - with ProxySQL 80

81 Failover scenario - with ProxySQL 81

82 Failover scenario - with ProxySQL 82

83 Failover without ProxySQL (10 minute outage) 83

84 Failover with ProxySQL (10 second outage) 84

85 Failover - MySQL Servers mysql> SELECT hostgroup_id, hostname, status FROM mysql_servers WHERE hostname IN ('mysql1, 'mysql2 )\G *************************** 1. row *************************** hostgroup_id: 0 hostname: mysql1 status: ONLINE *************************** 2. row *************************** hostgroup_id: 1 hostname: mysql2 status: ONLINE 2 rows in set (0.00 sec) 85

86 Failover - Replication Hostgroups mysql> SELECT * FROM mysql_replication_hostgroups\g *************************** 1. row *************************** writer_hostgroup: 0 reader_hostgroup: 1 comment: 1 row in set (0.00 sec) 86

87 ProxySQL Failover ProTIP ProxySQL does not handle promotion or re-slaving External process needed, such as MHA or Orchestrator 87

88 Failover Demo Click to add text

89 New Features Click to add text

90 ClickHouse Server New in experimental (not fully completed, subject to change) Support for ClickHouse: Fast, really fast data analytics using MySQL client Users management Supports only one backend Supports only DDL and SELECT (no INSERT)

91 ClickHouse Server

92 ClickHouse Server

93 SQLite3 Server New in experimental (not fully completed, subject to change) Support for SQLite3 : Fully transactional, in-memory Same users as MySQL backends A lot of features in the roadmap

94 You-Name-It Server What other service should become part of ProxySQL?

95 You-Name-It Server What other service should become part of ProxySQL?

96 Causal read with GTID Feature introduced in 2.0 Ensures that reads sent to slave returns what the client has written on master Requires GTID and MySQL 5.7+

97 ProxSQL Read / Write Split 97

98 ProxySQL Binlog Reader 98

99 ProxySQL Binlog Reader 99

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