我有一台运行MySQL的Linux服务器，其中包含：
-12 Gb RAM
-4 x Intel(R) Xeon(R) CPU E6510 @ 1.73GHz
-CentOS release 6.3
-MySQL 5.1.61
由于一些技术问题，我们不得不将服务器的RAM内存减少到8 GB，而目前我们无法拥有任何内存。现在，正因为如此，我们的服务器上出现了很多性能问题。这是我们DB的大小：
+--------+--------------------+---------+--------+--------+------------+---------+
| tables | table_schema | rows | data | idx | total_size | idxfrac |
+--------+--------------------+---------+--------+--------+------------+---------+
| 43 | XXXXXXXX | 142.81M | 10.52G | 13.31G | 23.83G | 1.27 |
| 44 | Test_XXXXXXXX | 55.20M | 3.57G | 4.77G | 8.33G | 1.34 |
| 34 | XXXXXXXXXXXXXXXX | 23.04M | 1.39G | 1.84G | 3.24G | 1.32 |
| 23 | mysql | 0.00M | 0.00G | 0.00G | 0.00G | 0.16 |
| 28 | information_schema | NULL | 0.00G | 0.00G | 0.00G | NULL |
+--------+--------------------+---------+--------+--------+------------+---------+
这是/etc/my.cnf的内容：
[mysqld]
max_allowed_packet = 1024M
sort_buffer_size = 512M
max_connections=500
query_cache_size = 512M
query_cache_limit = 512M
query-cache-type = 2
table_cache = 800
thread_cache_size=8
key_buffer_size = 512M
read_buffer_size=64M
read_rnd_buffer_size=64M
myisam_sort_buffer_size=64M
innodb_flush_log_at_trx_commit=2
innodb_buffer_pool_size=7000M
innodb_additional_mem_pool_size=100M
...
我不知道我是否能够真正确定大小和RAM之间的关系。但情况是，当我有12GB内存时，一切正常。 “innodb_buffer_pool_size”值为10000M，性能非常好。但现在，采取相同的操作，如4倍。
我们的应用程序基本上是一个数据库导出器，主要只接受一个表，它有72,314,541个寄存器。
+--------+---------+--------+--------+------------+---------+
| tables | rows | data | idx | total_size | idxfrac |
+--------+---------+--------+--------+------------+---------+
| 9 | 159.12M | 11.07G | 15.87G | 26.94G | 1.43 |
+--------+---------+--------+--------+------------+---------+
现在我们正在测试更改“innodb_buffer_pool_size”的值，但看起来我们不会获得更多的表演。现在，问题是，我们可以做些什么来在我们的MySQL上获得更多性能？
-Put more RAM (obviously)
-Change more variables on /etc/my.cnf?
-MySQL Partitioning for Performance
-...
欢迎所有的想法和贡献，
提前致谢
修改：添加了表格和查询的所有信息
DB的结构是一个从一些传感器接收信息并存储它的系统。
测量表：我们从传感器接收的测量结果。
+--------------------+------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+--------------------+------------+------+-----+---------+----------------+
| id | bigint(20) | NO | PRI | NULL | auto_increment |
| version | bigint(20) | NO | | NULL | |
| counter | char(2) | YES | | NULL | |
| datemeasurement_id | datetime | NO | MUL | NULL | |
| datereal_id | datetime | NO | MUL | NULL | |
| delayed | bit(1) | NO | | NULL | |
| frequency | tinyint(4) | YES | | NULL | |
| measuringentity_id | bigint(20) | NO | MUL | NULL | |
| real | bit(1) | NO | | NULL | |
| tamper | bit(1) | NO | | NULL | |
| value | float | NO | | NULL | |
+--------------------+------------+------+-----+---------+----------------+
measuring_entity表：一个传感器可以测量多个物体（温度，湿度）。这些都是实体。
+--------------+------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+--------------+------------+------+-----+---------+----------------+
| id | bigint(20) | NO | PRI | NULL | auto_increment |
| version | bigint(20) | NO | | NULL | |
| household_id | varchar(4) | NO | MUL | NULL | |
| operative | bit(1) | NO | | NULL | |
| type | char(20) | NO | | NULL | |
| unit | char(3) | NO | | NULL | |
| interval | float | YES | | NULL | |
+--------------+------------+------+-----+---------+----------------+
sensor_measuring_entity：一个传感器可以关联多个实体。
+--------------------+------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+--------------------+------------+------+-----+---------+-------+
| sensor_id | bigint(20) | NO | PRI | NULL | |
| measuringentity_id | bigint(20) | NO | PRI | NULL | |
| version | bigint(20) | NO | | NULL | |
+--------------------+------------+------+-----+---------+-------+
传感器表：传感器的信息，与上表中的测量实体相关。
+---------------------+-------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+---------------------+-------------+------+-----+---------+----------------+
| id | bigint(20) | NO | PRI | NULL | auto_increment |
| version | bigint(20) | NO | | NULL | |
| battery | bit(1) | NO | | NULL | |
| identifier | char(6) | NO | | NULL | |
| installationdate_id | datetime | NO | MUL | NULL | |
| lastreceiveddate_id | datetime | YES | MUL | NULL | |
| location_id | bigint(20) | NO | MUL | NULL | |
| operative | bit(1) | NO | | NULL | |
| tampererror | smallint(6) | NO | | NULL | |
+---------------------+-------------+------+-----+---------+----------------+
位置表：放置传感器的位置。
+------------+------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+------------+------------+------+-----+---------+----------------+
| id | bigint(20) | NO | PRI | NULL | auto_increment |
| version | bigint(20) | NO | | NULL | |
| height | tinyint(4) | YES | | NULL | |
| operative | bit(1) | NO | | NULL | |
| place | char(15) | NO | MUL | NULL | |
| room | char(15) | NO | | NULL | |
| typesensor | char(15) | NO | | NULL | |
| formaster | bit(1) | YES | | NULL | |
+------------+------------+------+-----+---------+----------------+
这是查询（适用于所有房屋和所有传感器）：
for (int z = 0; z < allHouses.length; z++) {
for (int j = 0; j < sensorlist.length; j++) {
sql.eachRow ("SELECT m.datemeasurement_id, s.identifier, me.type, m.value"
+ " FROM measurement as m"
+ " JOIN measuring_entity as me ON m.measuringentity_id = me.id"
+ " JOIN sensor_measuring_entity as sme ON sme.measuringentity_id = me.id"
+ " JOIN sensor as s ON sme.sensor_id = s.id"
+ " WHERE me.id = $actualmeid"
+ " AND me.household_id = '$mHouse'"
+ " AND m.datemeasurement_id >= '$cons_startDate'"
+ " AND m.datemeasurement_id <= '$cons_endDate'"
+ " AND m.datemeasurement_id > '$startDate'"
+ " AND m.datemeasurement_id < '$endDate'"
+ " ORDER BY datemeasurement_id")
{
}}
PD：一切都是Grails应用程序的一部分。
答案 0 :(得分：2)
您正在分配太多RAM并进行交换。交换比缩小设置要糟糕得多。
对于你的 8GB，建议进行这些更改
innodb_buffer_pool_size = 5000M query_cache_size = 50M
如果您说您使用的是MyISAM还是InnoDB，我会给您更多提示。