一、概述
X-Tuner 是一款数据库集成的参数调优工具，通过结合深度强化学习和全局搜索算法等AI技术，实现在无需人工干预的情况下，获取最佳数据库参数配置。本功能不强制与数据库环境部署到一起，支持独立部署，脱离数据库安装环境独立运行。
二、使用准备
前提条件与使用事项
- 数据库状态正常、客户端能够正常连接、且要求数据库内导入数据，以便调优程序可以执行benchmark测试调优效果。
- 使用本工具需要指定登录到数据库的用户身份，要求该登录到数据库上的用户具有足够的权限，以便可以获得充足的数据库状态信息。
- 使用登录到数据库宿主机上的Linux用户，需要将$GAUSSHOME/bin添加到PATH环境变量中，即能够直接运行gsql、gs_guc、gs_ctl等数据库运维工具。
- Python版本建议为Python3.6及以上，且运行环境中已经安装相应依赖，并能够正常启动调优程序。您可以独立安装一个python3.6+的环境，无需设置到全局环境变量中。不建议使用root用户权限安装本工具，如果以root身份安装本完毕工具，使用其他用户身份运行本工具时，需要确保配置文件有读取权限。
- 本工具支持以三种模式运行，其中tune和train模式要求用户配置好benchmark运行环境，并导入数据，本工具将会通过迭代运行benchmark来判断修改后的参数是否有性能提升。
- recommend模式建议在数据库正在执行workload的过程中执行，以便获得更准确的实时workload信息。
- 本工具默认带有TPC-C、TPC-H、TPC-DS以及sysbench的benchmark运行脚本样例，如果用户使用上述benchmark对数据库系统进行压力测试，则可以对上述配置文件进行适度修改或配置。如果需要适配用户自己的业务场景，需要您参照benchmark目录中的template.py文件编写驱动您自定义benchmark的脚本文件。
三、原理简介
调优程序是一个独立于数据库内核之外的工具，需要提供数据库及其所在实例的用户名和登录密码信息，以便控制数据库执行benchmark进行性能测试；在启动调优程序前，要求用户测试环境交互正常，能够正常跑通benchmark测试脚本、能够正常连接数据库。
X-Tuner运行模式
- recommend: 通过用户指定的用户名等信息登录到数据库环境中，获取当前正在运行的workload特征信息，根据上述特征信息生成参数推荐报告。报告当前数据库中不合理的参数配置和潜在风险等；输出根据当前正在运行的workload行为和特征；输出推荐的参数配置。 该模式是秒级的，不涉及数据库的重启操作，其他模式可能需要反复重启数据库。
- train: 通过用户提供的benchmark信息，不断地进行参数修改和benchmark的执行。通过反复的迭代过程，训练强化学习模型，以便用户在后面通过tune模式加载该模型进行调优。
- tune: 使用优化算法进行数据库参数的调优，当前支持两大类算法，一种是深度强化学习，另一种是全局搜索算法（全局优化算法）。深度强化学习模式要求先运行train模式，生成训练后的调优模型，而使用全局搜索算法则不需要提前进行训练，可以直接进行搜索调优。
X-Tuner架构图
- DB侧：通过DB_Agent 模块对数据库实例进行抽象，通过该模块可以获取数据库内部的状态信息、当前数据库参数、以及设置数据库参数等。DB侧包括登录数据库环境使用的SSH连接。
- 算法侧：用于调优的算法包，包括全局搜索算法（如贝叶斯优化、粒子群算法等）和深度强化学习（如DDPG）；
- X-Tuner 主体逻辑模块：通过Enviroment模块进行封装，每一个step 就是一次调优过程。整个调优过程通过多个step进行迭代；
- benchmark: 由用户指定的benchmark性能测试脚本，用于运行benchmark作业，通过跑分结果反映数据库系统性能优劣。
四、X-Tuner安装
1. 程序位置
- 源码位置
[root@ecs-saving-0008 xtuner]# pwd /root/openGauss-server/src/gausskernel/dbmind/tools/xtuner
- 已安装过的数据库
[omm@ecs-saving-0001 ~]$ cd $GAUSSHOME/bin/dbmind/xtuner [omm@ecs-saving-0001 xtuner]$ pwd /opengauss/app/1.0.1/bin/dbmind/xtuner
2. 安装依赖
[root@ecs-saving-0008 xtuner]# ls build dist openGauss_xtuner.egg-info Readme.md requirements.txt setup.py share test tuner [root@ecs-saving-0008 xtuner]# pip3 install --upgrade pip [root@ecs-saving-0008 xtuner]# pip3 install -r requirements.txt [root@ecs-saving-0008 xtuner]# cat requirements.txt tensorflow>=2.2.0 keras-rl2 paramiko bayesian-optimization ptable [root@ecs-saving-0008 xtuner]# pip3 install keras
默认网站较慢建议学会科学上网，手动解决依赖。
3. 安装X-Tuner
[root@ecs-saving-0008 xtuner]# pwd /root/openGauss-server/src/gausskernel/dbmind/tools/xtuner [root@ecs-saving-0008 xtuner]# python3 setup.py install [root@ecs-saving-0008 xtuner]# gs_xtuner --help usage: gs_xtuner [-h] [--db-name DB_NAME] [--db-user DB_USER] [--port PORT] [--host HOST] [--host-user HOST_USER] [--host-ssh-port HOST_SSH_PORT] [-f DB_CONFIG_FILE] [-x TUNER_CONFIG_FILE] [-v] {train,tune,recommend} X-Tuner: a self-tuning tool integrated by openGauss. positional arguments: {train,tune,recommend} Train a reinforcement learning model or tune database by model. And also can recommend best_knobs according to your workload. optional arguments: -h, --help show this help message and exit -f DB_CONFIG_FILE, --db-config-file DB_CONFIG_FILE You can pass a path of configuration file otherwise you should enter database information by command arguments manually. Please see the template file share/server.json.template. -x TUNER_CONFIG_FILE, --tuner-config-file TUNER_CONFIG_FILE This is the path of the core configuration file of the X-Tuner. You can specify the path of the new configuration file. The default path is /usr/local/lib/python3.6/site-packages/openGauss_xtune r-2.0.0-py3.6.egg/tuner/xtuner.conf. You can modify the configuration file to control the tuning process. -v, --version show program's version number and exit Database Connection Information: --db-name DB_NAME The name of database where your workload running on. --db-user DB_USER Use this user to login your database. Note that the user must have sufficient permissions. --port PORT Use this port to connect with the database. --host HOST The IP address of your database installation host. --host-user HOST_USER The login user of your database installation host. --host-ssh-port HOST_SSH_PORT The SSH port of your database installation host.
五、文件解读
[root@ecs-saving-0008 tools]# pwd /root/openGauss-server/src/gausskernel/dbmind/tools [root@ecs-saving-0008 tools]# ls anomaly_detection index_advisor predictor sqldiag xtuner
分别为五个AI功能，后续文章会逐一介绍。
- Anomaly-detection：数据库指标采集、预测与异常监控
- Index-advisor：索引推荐
- Predictor: AI查询时间预测
- SQLdiag: 慢SQL发现
- X-Tuner: 参数调优与诊断
[root@ecs-saving-0008 benchmark]# pwd /root/openGauss-server/src/gausskernel/dbmind/tools/xtuner/tuner/benchmark __init__.py Readme.md sysbench.py template.py tpcc.py tpcds.py tpch.py
需提前调试好相关程序并生成测试数据
- benchmark 模拟压力模型，支持 sysbench.py template.py tpcc.py tpcds.py tpch.py
- 在使用tune和train 模式前，用户需要先导入benchmark所需数据并检查benchmark能否正常跑通，并备份好此时的数据库参数，查询当前数据库参数的方法为：select name, setting from pg_settings;
- 目前tpcc测试程序相关代码有问题，暂时手动模拟压力解决。
配置文件解读
[root@ecs-saving-0008 tuner]# cat xtuner.conf |grep -v ^$|grep -v ^# [Master] logfile = log/opengauss_tuner.log output_tuning_result = tuned_knobs.json verbose = on recorder_file = log/recorder.log tune_strategy = auto # rl, gop or auto drop_cache = on # You must modify the permission of the login user in the /etc/sudoers file and grant the NOPASSWD permission to the user. used_mem_penalty_term = 1e-9 # Prevent taking up more memory. [Reinforcement Learning] rl_algorithm = ddpg # ddpg, dqn. Not support dqn yet. rl_model_path = model/rl.model rl_steps = 100 max_episode_steps = 10 test_episode = 1 [Gloabal Optimization Algorithm] gop_algorithm = bayes # bayes, pso max_iterations = 100 particle_nums = 3 # A larger value indicates higher accuracy but slower speed. [Benchmark] benchmark_script = tpcc benchmark_path = '/opt/benchmarksql-5.0/run' # If this parameter is blank, the default path in the benchmark script is used. benchmark_cmd = "./runBenchmark.sh props.og" # If this parameter is blank, the default cmd in the benchmark script is used. [Knobs] scenario = auto # ap, tp, htap or auto tuning_list = # template: share/knobs.json.template
- rl_algorithm：用于训练强化学习模型的算法，当前支持设置为ddpg.
- rl_model_path: 训练后生成的强化学习模型保存路径。
- rl_steps：训练过程的最大迭代步数。
- max_episode_steps：每个回合的最大步数。
- scenario: 明确指定的workload类型，如果为auto则为自动判断。在不同模式下，推荐的调优参数列表也不一样。
- tuning_list: 用户指定需要调哪些参数，如果不指定，则根据workload类型自动推荐应该调的参数列表。
- tune_strategy: 指定选择哪种算法进行调优，支持rl（使用强化学习模型进行调优）、gop （使用全局搜索算法）以及 aut- （自动选择）。若该参数设置为rl，则rl相关的配置项生效。除前文提到过的train模式下生效的配置项外，test_episode配置项- 生效，该配置项表明调优过程的最大回合数，该参数直接影响了调优过程的执行时间（一般地，数值越大越耗时）。
- gop_algorithm: 选择何种全局搜索算法，支持bayes以及pso.
- max_iterations: 最大迭代轮次，数值越高搜索时间越长，效果往往越好。
- particle_nums: 在PSO算法上生效，表示粒子数。
- scenario 与 tuning_list 见上文 train 模式中的描述。
- drop_cache = on 需修改/etc/sudoers文件 添加如下 username ALL=(ALL) NOPASSWD: ALL
六、使用示例
X-Tuner 支持三种模式，分别是获取参数诊断报告的recommend模式、训练强化学习模型的train模式、以及使用算法进行调优的tune模式。上述三种模式可以通过命令行参数来区别，通过配置文件来指定具体的细节。
1. 配置数据库连接信息
有两种方式
- a. 通过命令行执行
[root@ecs-saving-0008 xtuner]# gs_xtuner recommend --db-name test1 --db-user test1 --port 26000 --host 192.168.1.XXX --host-user omm -x xtuner.conf
- b. json配置文件
[root@ecs-saving-0008 tuner]# cat connection.json { "db_name": "test1", "db_user": "test1", "host": "192.168.1.xxx", "host_user": "omm", "port": 26000, "ssh_port": 22 } [root@ecs-saving-0008 xtuner]# gs_xtuner recommend -f connection.json -x xtuner.conf
2. recommend 模式
[root@ecs-saving-0008 tuner]# gs_xtuner recommend --db-name test1 --db-user test1 --port 26000 --host 192.168.1.xxx --host-user omm Please input the password of database: Please input the password of host: Start to recommend knobs. Just a moment, please. ******************************************************* Knob Recommendation Report ******************************************************* INFO: +---------------------------------------+-----------------------+ | Metric | Value | +---------------------------------------+-----------------------+ | workload_type | tp | | dirty_background_bytes | 0 | | temp_file_size | 0 | | current_locks_count | 0.0 | | current_prepared_xacts_count | 0.0 | | average_connection_age | 0.013457 | | checkpoint_proactive_triggering_ratio | 0.0413987138263666 | | rollback_commit_ratio | 0.07913229312035018 | | fetched_returned_ratio | 0.3706085439318767 | | cache_hit_rate | 0.9780311156824839 | | current_connections | 1.0 | | uptime | 1.48835260083333 | | search_modify_ratio | 119.88027537957866 | | all_database_size | 1436801.01171875 | | current_free_mem | 15400044 | | os_mem_total | 16430884 | | checkpoint_avg_sync_time | 2.03215434083601 | | read_write_ratio | 2.1202316810075224 | | ap_index | 2.1987815358313485 | | max_processes | 3010 | | track_activity_size | 3010.0 | | used_mem | 3155124224.0 | | write_tup_speed | 374.211175655672 | | os_cpu_count | 4 | | checkpoint_dirty_writing_time_window | 720.0 | | read_tup_speed | 793.422421264566 | | block_size | 8.0 | | shared_buffer_toast_hit_rate | 91.9572192513369 | | shared_buffer_heap_hit_rate | 99.5745962509106 | | shared_buffer_idx_hit_rate | 99.67849101944427 | | shared_buffer_tidx_hit_rate | 99.78536585365853 | | is_hdd | False | | enable_autovacuum | True | | is_64bit | True | | load_average | [0.26, 0.5375, 0.525] | +---------------------------------------+-----------------------+ p.s: The unit of storage is kB. WARN: [0]. The total size of all databases is less than the memory size. Therefore, it is unnecessary to set shared_buffers to a large value. [1]. The database runs for a short period of time, and the database description may not be accumulated. The recommendation result may be inaccurate. [2]. The number of CPU cores is a little small. Please do not run too high concurrency. You are recommended to set max_connections based on the number of CPU cores. If your job does not consume much CPU, you can also increase it. BAD: [0]. The value of wal_buffers is too high. Generally, a large value does not bring better performance. ******************************************************** Recommended Knob Settings ******************************************************** +---------------------------+-----------+--------+----------+---------+ | name | recommend | min | max | restart | +---------------------------+-----------+--------+----------+---------+ | shared_buffers | 179600 | 179600 | 206540 | True | | max_connections | 100 | 20 | 500 | True | | effective_cache_size | 179600 | 179600 | 12323163 | False | | effective_io_concurrency | 200 | 150 | 250 | False | | wal_buffers | 5612 | 2048 | 5612 | True | | random_page_cost | 1.0 | 1.0 | 2.0 | False | | default_statistics_target | 100 | 10 | 150 | False | +---------------------------+-----------+--------+----------+---------+
在上述报告中，推荐了该环境上的数据库参数配置，并进行了风险提示。报告同时生成了当前workload的特征信息，其中有几个特征是比较有参考意义的：
- temp_file_size：产生的临时文件数量，如果该结果大于0，则表明系统使用了临时文件。使用过多的临时文件会导致性能不佳，如果可能的话，需要提高work_mem参数的配置。
- cache_hit_rate：shared_buffer 的缓存命中率，表明当前workload使用缓存的效率。
- read_write_ratio：数据库作业的读写比例。
- search_modify_ratio：数据库作业的查询与修改数据的比例。
- ap_index：表明当前workload的AP指数，取值范围是0到10，该数值越大，表明越偏向于数据分析与检索。
- workload_type：根据数据库统计信息，推测当前负载类型，分为AP、TP以及HTAP三种类型。
- checkpoint_avg_sync_time：数据库在checkpoint 时，平均每次同步刷新数据到磁盘的时长，单位是毫秒。
- load_average：平均每个CPU核心在1分钟、5分钟以及15分钟内的负载。一般地，该数值在1左右表明当前硬件比较匹配workload、在3左右表明运行当前作业压力比较大，大于5则表示当前硬件环境运行该workload压力过大（此时一般建议减少负载或升级硬件）。
- recommend 模式会读取数据库中的pg_stat_database以及 pg_stat_bgwriter等系统表中的信息，需要登录到数据库上的用户具有足够的权限（建议为管理员权限，可通过alter user username sysadmin；授予username相应的权限）。
- 由于某些系统表会一直记录统计信息，这可能会对负载特征识别造成干扰，因此建议最好先清空某些系统表的统计信息，运行一段时间的workload后再使用recommend模式进行诊断，以便获得更准确的结果。清除统计信息的方法为：
- select pg_stat_reset_shared(‘bgwriter’);
- select pg_stat_reset();
3. train 模式
[root@ecs-saving-0008 tuner]# gs_xtuner train -f connection.json -x xtuner.conf Please input the password of database: Please input the password of host: Start to recommend knobs. Just a moment, please. WARN: The database may restart several times during tuning, continue or not [yes|no]:yes 2021-01-17 15:48:20,864: Recorder is starting. 2021-01-17 15:48:21.423844: W tensorflow/stream_executor/platform/default/dso_loader.cc:60] Could not load dynamic library 'libcudart.so.11.0'; dlerror: libcudart.so.11.0: cannot open shared object file: No such file or directory 2021-01-17 15:48:21.423910: I tensorflow/stream_executor/cuda/cudart_stub.cc:29] Ignore above cudart dlerror if you do not have a GPU set up on your machine. Adam 2021-01-17 15:48:24.022924: I tensorflow/compiler/jit/xla_cpu_device.cc:41] Not creating XLA devices, tf_xla_enable_xla_devices not set 2021-01-17 15:48:24.023181: W tensorflow/stream_executor/platform/default/dso_loader.cc:60] Could not load dynamic library 'libcuda.so.1'; dlerror: libcuda.so.1: cannot open shared object file: No such file or directory 2021-01-17 15:48:24.023212: W tensorflow/stream_executor/cuda/cuda_driver.cc:326] failed call to cuInit: UNKNOWN ERROR (303) 2021-01-17 15:48:24.023246: I tensorflow/stream_executor/cuda/cuda_diagnostics.cc:156] kernel driver does not appear to be running on this host (ecs-saving-0008): /proc/driver/nvidia/version does not exist 2021-01-17 15:48:24.023773: I tensorflow/core/platform/cpu_feature_guard.cc:142] This TensorFlow binary is optimized with oneAPI Deep Neural Network Library (oneDNN) to use the following CPU instructions in performance-critical operations: AVX512F To enable them in other operations, rebuild TensorFlow with the appropriate compiler flags. 2021-01-17 15:48:24.024250: I tensorflow/compiler/jit/xla_gpu_device.cc:99] Not creating XLA devices, tf_xla_enable_xla_devices not set 2021-01-17 15:48:24.052176: I tensorflow/compiler/mlir/mlir_graph_optimization_pass.cc:196] None of the MLIR optimization passes are enabled (registered 0 passes) 2021-01-17 15:48:24.057462: I tensorflow/core/platform/profile_utils/cpu_utils.cc:112] CPU Frequency: 2600000000 Hz The list of tuned knobs in the training mode based on the reinforcement learning algorithm must be the same as that in the tuning mode. /usr/local/lib64/python3.6/site-packages/tensorflow/python/keras/engine/training.py:2325: UserWarning: `Model.state_updates` will be removed in a future version. This property should not be used in TensorFlow 2.0, as `updates` are applied automatically. warnings.warn('`Model.state_updates` will be removed in a future version. ' 2021-01-17 15:48:50,022: [0] Current reward is -3.256027, knobs: {'shared_buffers': '213807'}. 2021-01-17 15:48:50,022: [0] Best reward is -3.256027, knobs: {'shared_buffers': '213807'}. 2021-01-17 15:48:50,022: [1] Database metrics: [0.5051657050852006, 0.975755080057054, 0.2125]. 2021-01-17 15:48:50,023: [1] Benchmark score: -0.103773, used mem: 3152253680 kB, reward: -3.256027. 2021-01-17 15:49:15,193: [1] Current reward is -3.255776, knobs: {'shared_buffers': '228559'}. 2021-01-17 15:49:15,194: [1] Best reward is -3.255776, knobs: {'shared_buffers': '228559'}. 2021-01-17 15:49:15,194: [2] Database metrics: [1.0, 0.9757370052274821, 0.18]. 2021-01-17 15:49:15,194: [2] Benchmark score: -0.103286, used mem: 3152489712 kB, reward: -3.255776. 2021-01-17 15:49:40,384: [2] Current reward is -3.256460, knobs: {'shared_buffers': '213646'}. 2021-01-17 15:49:40,384: [2] Best reward is -3.255776, knobs: {'shared_buffers': '228559'}. 2021-01-17 15:49:40,385: [3] Database metrics: [0.49976519522339996, 0.9757370052274821, 0.12]. 2021-01-17 15:49:40,385: [3] Benchmark score: -0.104209, used mem: 3152251104 kB, reward: -3.256460. 2021-01-17 15:50:05,542: [3] Current reward is -3.256012, knobs: {'shared_buffers': '220718'}. 2021-01-17 15:50:05,542: [3] Best reward is -3.255776, knobs: {'shared_buffers': '228559'}. 2021-01-17 15:50:05,542: [4] Database metrics: [0.7369851066684556, 0.975755080057054, 0.1075]. 2021-01-17 15:50:05,543: [4] Benchmark score: -0.103648, used mem: 3152364256 kB, reward: -3.256012. 2021-01-17 15:50:30,691: [4] Current reward is -3.256337, knobs: {'shared_buffers': '207214'}. 2021-01-17 15:50:30,691: [4] Best reward is -3.255776, knobs: {'shared_buffers': '228559'}. 2021-01-17 15:50:30,691: [5] Database metrics: [0.2840131490674896, 0.975755080057054, 0.0925]. 2021-01-17 15:50:30,692: [5] Benchmark score: -0.104188, used mem: 3152148192 kB, reward: -3.256337. ****************************************************************************************************** Knob Recommendation Report ****************************************************************************************************** INFO: +---------------------------------------+------------------------+ | Metric | Value | +---------------------------------------+------------------------+ | workload_type | ap | | dirty_background_bytes | 0 | | temp_file_size | 0 | | current_locks_count | 0.0 | | current_prepared_xacts_count | 0.0 | | rollback_commit_ratio | 0.0 | | write_tup_speed | 0.0 | | average_connection_age | 0.012783 | | uptime | 0.101278143888889 | | fetched_returned_ratio | 0.18264946102405455 | | checkpoint_proactive_triggering_ratio | 0.195960870937204 | | cache_hit_rate | 0.9871855024265209 | | current_connections | 1.0 | | current_free_mem | 15428064 | | all_database_size | 1589977.01171875 | | os_mem_total | 16430884 | | checkpoint_avg_sync_time | 2.64405175134112 | | search_modify_ratio | 20120500.0 | | read_write_ratio | 201205000.0 | | max_processes | 3010 | | track_activity_size | 3010.0 | | used_mem | 3152427664.0 | | os_cpu_count | 4 | | read_tup_speed | 419.743636679271 | | ap_index | 6.7 | | checkpoint_dirty_writing_time_window | 720.0 | | shared_buffer_toast_hit_rate | 76.40449438202248 | | block_size | 8.0 | | shared_buffer_tidx_hit_rate | 94.7103274559194 | | shared_buffer_heap_hit_rate | 99.50838310887633 | | shared_buffer_idx_hit_rate | 99.52046667292409 | | is_hdd | False | | enable_autovacuum | True | | is_64bit | True | | load_average | [0.255, 0.225, 0.2125] | +---------------------------------------+------------------------+ p.s: The unit of storage is kB. WARN: [0]. The number of CPU cores is a little small. Please do not run too high concurrency. You are recommended to set max_connections based on the number of CPU cores. If your job does not consume much CPU, you can also increase it. [1]. The total size of all databases is less than the memory size. Therefore, it is unnecessary to set shared_buffers to a large value. BAD: [0]. The value of wal_buffers is too high. Generally, a large value does not bring better performance. ****************************************************************************************************** Recommended Knob Settings ****************************************************************************************************** +---------------------------+-----------+--------+----------+---------+ | name | recommend | min | max | restart | +---------------------------+-----------+--------+----------+---------+ | shared_buffers | 198747 | 198747 | 228559 | True | | max_connections | 185 | 15 | 370 | True | | effective_cache_size | 12323163 | 198747 | 12323163 | False | | effective_io_concurrency | 200 | 150 | 250 | False | | wal_buffers | 6210 | 2048 | 6210 | True | | random_page_cost | 1.0 | 1.0 | 2.0 | False | | default_statistics_target | 1000 | 100 | 1000 | False | +---------------------------+-----------+--------+----------+---------+
训练完成后，会在配置项rl_model_path指定的目录中生成模型文件。
4. tune 模式
[root@ecs-saving-0008 tuner]# gs_xtuner tune -f connection.json -x xtuner.conf Please input the password of database: Please input the password of host: Start to recommend knobs. Just a moment, please. WARN: The database may restart several times during tuning, continue or not [yes|no]:yes 2021-01-17 15:52:56,212: Recorder is starting. | iter | target | effect... | random... | ------------------------------------------------- 2021-01-17 15:52:59,473: [0] Current reward is -3.255687, knobs: {'effective_io_concurrency': '172', 'random_page_cost': '1.34'}. 2021-01-17 15:52:59,473: [0] Best reward is -3.255687, knobs: {'effective_io_concurrency': '172', 'random_page_cost': '1.34'}. 2021-01-17 15:52:59,473: [1] Database metrics: [0.22, 0.3400000000000001, 0.9848556082330464, 0.2575]. 2021-01-17 15:52:59,474: [1] Benchmark score: -0.103539, used mem: 3152148192 kB, reward: -3.255687. | 1 | -3.256 | 0.223 | 0.3392 | 2021-01-17 15:53:01,612: [1] Current reward is -3.256332, knobs: {'effective_io_concurrency': '171', 'random_page_cost': '1.02'}. 2021-01-17 15:53:01,613: [1] Best reward is -3.255687, knobs: {'effective_io_concurrency': '172', 'random_page_cost': '1.34'}. 2021-01-17 15:53:01,614: [2] Database metrics: [0.21, 0.020000000000000018, 0.9851427720903616, 0.2575]. 2021-01-17 15:53:01,614: [2] Benchmark score: -0.104184, used mem: 3152148192 kB, reward: -3.256332. | 2 | -3.256 | 0.2139 | 0.01739 | 2021-01-17 15:53:03,664: [2] Current reward is -3.256156, knobs: {'effective_io_concurrency': '226', 'random_page_cost': '1.28'}. 2021-01-17 15:53:03,664: [2] Best reward is -3.255687, knobs: {'effective_io_concurrency': '172', 'random_page_cost': '1.34'}. 2021-01-17 15:53:03,665: [3] Database metrics: [0.76, 0.28, 0.9854192483562304, 0.2575]. 2021-01-17 15:53:03,665: [3] Benchmark score: -0.104007, used mem: 3152148192 kB, reward: -3.256156. | 3 | -3.256 | 0.7578 | 0.2831 | 2021-01-17 15:53:05,681: [3] Current reward is -3.256023, knobs: {'effective_io_concurrency': '200', 'random_page_cost': '1.35'}. 2021-01-17 15:53:05,682: [3] Best reward is -3.255687, knobs: {'effective_io_concurrency': '172', 'random_page_cost': '1.34'}. 2021-01-17 15:53:05,682: [4] Database metrics: [0.5, 0.3500000000000001, 0.9856856227825624, 0.2575]. 2021-01-17 15:53:05,682: [4] Benchmark score: -0.103875, used mem: 3152148192 kB, reward: -3.256023. | 4 | -3.256 | 0.5007 | 0.345 | 2021-01-17 15:53:07,728: [4] Current reward is -3.255765, knobs: {'effective_io_concurrency': '158', 'random_page_cost': '1.29'}. 2021-01-17 15:53:07,728: [4] Best reward is -3.255687, knobs: {'effective_io_concurrency': '172', 'random_page_cost': '1.34'}. 2021-01-17 15:53:07,728: [5] Database metrics: [0.08, 0.29000000000000004, 0.9859424390850301, 0.2575]. 2021-01-17 15:53:07,729: [5] Benchmark score: -0.103617, used mem: 3152148192 kB, reward: -3.255765. | 5 | -3.256 | 0.08186 | 0.2852 | 2021-01-17 15:53:09,892: [5] Current reward is -3.255949, knobs: {'effective_io_concurrency': '163', 'random_page_cost': '1.47'}. 2021-01-17 15:53:09,892: [5] Best reward is -3.255687, knobs: {'effective_io_concurrency': '172', 'random_page_cost': '1.34'}. 2021-01-17 15:53:09,892: [6] Database metrics: [0.13, 0.47, 0.9861902026474977, 0.275]. 2021-01-17 15:53:09,892: [6] Benchmark score: -0.103801, used mem: 3152148192 kB, reward: -3.255949. | 6 | -3.256 | 0.1274 | 0.4671 | 2021-01-17 15:53:12,043: [6] Current reward is -3.256464, knobs: {'effective_io_concurrency': '181', 'random_page_cost': '1.43'}. 2021-01-17 15:53:12,043: [6] Best reward is -3.255687, knobs: {'effective_io_concurrency': '172', 'random_page_cost': '1.34'}. 2021-01-17 15:53:12,043: [7] Database metrics: [0.31, 0.42999999999999994, 0.9864293838414936, 0.275]. 2021-01-17 15:53:12,044: [7] Benchmark score: -0.104316, used mem: 3152148192 kB, reward: -3.256464. | 7 | -3.256 | 0.3105 | 0.4275 | 2021-01-17 15:53:14,118: [7] Current reward is -3.256466, knobs: {'effective_io_concurrency': '164', 'random_page_cost': '1.31'}. 2021-01-17 15:53:14,118: [7] Best reward is -3.255687, knobs: {'effective_io_concurrency': '172', 'random_page_cost': '1.34'}. 2021-01-17 15:53:14,118: [8] Database metrics: [0.14, 0.31000000000000005, 0.9866604210066019, 0.295]. 2021-01-17 15:53:14,119: [8] Benchmark score: -0.104318, used mem: 3152148192 kB, reward: -3.256466. | 8 | -3.256 | 0.138 | 0.3143 | 2021-01-17 15:53:16,193: [8] Current reward is -3.255741, knobs: {'effective_io_concurrency': '185', 'random_page_cost': '1.79'}. 2021-01-17 15:53:16,193: [8] Best reward is -3.255687, knobs: {'effective_io_concurrency': '172', 'random_page_cost': '1.34'}. 2021-01-17 15:53:16,194: [9] Database metrics: [0.35, 0.79, 0.9868837231315075, 0.295]. 2021-01-17 15:53:16,194: [9] Benchmark score: -0.103592, used mem: 3152148192 kB, reward: -3.255741. | 9 | -3.256 | 0.3464 | 0.7892 | 2021-01-17 15:53:18,292: [9] Current reward is -3.255511, knobs: {'effective_io_concurrency': '155', 'random_page_cost': '1.83'}. 2021-01-17 15:53:18,293: [9] Best reward is -3.255511, knobs: {'effective_io_concurrency': '155', 'random_page_cost': '1.83'}. 2021-01-17 15:53:18,293: [10] Database metrics: [0.05, 0.8300000000000001, 0.9870996722701926, 0.295]. 2021-01-17 15:53:18,293: [10] Benchmark score: -0.103362, used mem: 3152148192 kB, reward: -3.255511. | 10 | -3.256 | 0.05099 | 0.8299 | 2021-01-17 15:53:20,388: [10] Current reward is -3.255719, knobs: {'effective_io_concurrency': '183', 'random_page_cost': '1.58'}. 2021-01-17 15:53:20,388: [10] Best reward is -3.255511, knobs: {'effective_io_concurrency': '155', 'random_page_cost': '1.83'}. 2021-01-17 15:53:20,389: [11] Database metrics: [0.33, 0.5800000000000001, 0.9873086257233148, 0.31]. 2021-01-17 15:53:20,389: [11] Benchmark score: -0.103571, used mem: 3152148192 kB, reward: -3.255719. | 11 | -3.256 | 0.332 | 0.5833 | 2021-01-17 15:53:22,476: [11] Current reward is -3.255922, knobs: {'effective_io_concurrency': '224', 'random_page_cost': '1.8'}. 2021-01-17 15:53:22,477: [11] Best reward is -3.255511, knobs: {'effective_io_concurrency': '155', 'random_page_cost': '1.83'}. 2021-01-17 15:53:22,478: [12] Database metrics: [0.74, 0.8, 0.9875109180109677, 0.31]. 2021-01-17 15:53:22,478: [12] Benchmark score: -0.103774, used mem: 3152148192 kB, reward: -3.255922. | 12 | -3.256 | 0.7379 | 0.7979 | 2021-01-17 15:53:24,562: [12] Current reward is -3.256171, knobs: {'effective_io_concurrency': '246', 'random_page_cost': '1.9'}. 2021-01-17 15:53:24,562: [12] Best reward is -3.255511, knobs: {'effective_io_concurrency': '155', 'random_page_cost': '1.83'}. 2021-01-17 15:53:24,562: [13] Database metrics: [0.96, 0.8999999999999999, 0.9877068626597331, 0.325]. 2021-01-17 15:53:24,562: [13] Benchmark score: -0.104023, used mem: 3152148192 kB, reward: -3.256171. | 13 | -3.256 | 0.9551 | 0.9002 | 2021-01-17 15:53:26,676: [13] Current reward is -3.255921, knobs: {'effective_io_concurrency': '199', 'random_page_cost': '1.35'}. 2021-01-17 15:53:26,677: [13] Best reward is -3.255511, knobs: {'effective_io_concurrency': '155', 'random_page_cost': '1.83'}. 2021-01-17 15:53:26,677: [14] Database metrics: [0.49, 0.3500000000000001, 0.9878967538241067, 0.325]. 2021-01-17 15:53:26,677: [14] Benchmark score: -0.103773, used mem: 3152148192 kB, reward: -3.255921. | 14 | -3.256 | 0.4858 | 0.3522 | 2021-01-17 15:53:28,763: [14] Current reward is -3.255747, knobs: {'effective_io_concurrency': '153', 'random_page_cost': '1.83'}. 2021-01-17 15:53:28,764: [14] Best reward is -3.255511, knobs: {'effective_io_concurrency': '155', 'random_page_cost': '1.83'}. 2021-01-17 15:53:28,764: [15] Database metrics: [0.03, 0.8300000000000001, 0.9880808677599346, 0.325]. 2021-01-17 15:53:28,764: [15] Benchmark score: -0.103598, used mem: 3152148192 kB, reward: -3.255747. | 15 | -3.256 | 0.02704 | 0.8322 | ================================================= 2021-01-17 15:53:28,765: The tuning process is complete. The best reward is -3.255511, best knobs are: {'effective_io_concurrency': '155', 'random_page_cost': '1.83'}. ****************************************************************************************************** Knob Recommendation Report ****************************************************************************************************** INFO: +---------------------------------------+------------------------+ | Metric | Value | +---------------------------------------+------------------------+ | workload_type | ap | | dirty_background_bytes | 0 | | temp_file_size | 0 | | current_locks_count | 0.0 | | current_prepared_xacts_count | 0.0 | | rollback_commit_ratio | 0.0 | | write_tup_speed | 0.0 | | average_connection_age | 0.012993 | | uptime | 0.0202690916666667 | | fetched_returned_ratio | 0.15769242371706166 | | checkpoint_proactive_triggering_ratio | 0.203501094091904 | | cache_hit_rate | 0.9780674962419049 | | current_connections | 1.0 | | current_free_mem | 15532000 | | all_database_size | 1593746.21484375 | | os_mem_total | 16430884 | | checkpoint_avg_sync_time | 2.64145045326665 | | max_processes | 3010 | | track_activity_size | 3010.0 | | used_mem | 3152148192.0 | | os_cpu_count | 4 | | ap_index | 6.7 | | shared_buffer_toast_hit_rate | 63.41463414634146 | | checkpoint_dirty_writing_time_window | 720.0 | | block_size | 8.0 | | search_modify_ratio | 8616900.0 | | read_write_ratio | 86169000.0 | | shared_buffer_tidx_hit_rate | 91.66666666666667 | | read_tup_speed | 917.793974728196 | | shared_buffer_idx_hit_rate | 99.49449740875606 | | shared_buffer_heap_hit_rate | 99.54367629484318 | | is_hdd | False | | enable_autovacuum | True | | is_64bit | True | | load_average | [0.1125, 0.1625, 0.19] | +---------------------------------------+------------------------+ p.s: The unit of storage is kB. WARN: [0]. The total size of all databases is less than the memory size. Therefore, it is unnecessary to set shared_buffers to a large value. [1]. The number of CPU cores is a little small. Please do not run too high concurrency. You are recommended to set max_connections based on the number of CPU cores. If your job does not consume much CPU, you can also increase it. BAD: [0]. The value of wal_buffers is too high. Generally, a large value does not bring better performance. ****************************************************************************************************** Recommended Knob Settings ****************************************************************************************************** +---------------------------+-----------+--------+----------+---------+ | name | recommend | min | max | restart | +---------------------------+-----------+--------+----------+---------+ | random_page_cost | 1.83 | 1.0 | 2.0 | False | | effective_io_concurrency | 155 | 150 | 250 | False | | shared_buffers | 199218 | 199218 | 229101 | True | | max_connections | 184 | 15 | 369 | True | | effective_cache_size | 12323163 | 199218 | 12323163 | False | | wal_buffers | 6225 | 2048 | 6225 | True | | default_statistics_target | 1000 | 100 | 1000 | False |
