网站数据库经常挂，小白求助！

2 核 4G 的阿里云服务器，2M 带宽
/etc/my.cnf 的配置

[client]
port = 3306
socket = /tmp/mysql.sock
default-character-set = utf8mb4

[mysql]
prompt="MySQL [\d]> "
no-auto-rehash

[mysqld]
port = 3306
socket = /tmp/mysql.sock

basedir = /usr/local/mysql
datadir = /data/mysql
pid-file = /data/mysql/mysql.pid
user = mysql
bind-address = 0.0.0.0
server-id = 1

init-connect = 'SET NAMES utf8mb4'
character-set-server = utf8mb4

skip-name-resolve
#skip-networking
back_log = 300

max_connections = 1895
max_connect_errors = 6000
open_files_limit = 65535
table_open_cache = 1024
max_allowed_packet = 500M
binlog_cache_size = 1M
max_heap_table_size = 8M
tmp_table_size = 128M

read_buffer_size = 2M
read_rnd_buffer_size = 8M
sort_buffer_size = 8M
join_buffer_size = 8M
key_buffer_size = 256M

thread_cache_size = 64

query_cache_type = 1
query_cache_size = 64M
query_cache_limit = 2M

ft_min_word_len = 4

#log_bin = mysql-bin #不让 mysql 的操作日志文件生成
binlog_format = mixed
expire_logs_days = 7 #日志保存 7 天

log_error = /data/mysql/mysql-error.log
slow_query_log = 1
long_query_time = 1
slow_query_log_file = /data/mysql/mysql-slow.log

performance_schema = 0
explicit_defaults_for_timestamp

#lower_case_table_names = 1

skip-external-locking

default_storage_engine = InnoDB
innodb_file_per_table = 1
innodb_open_files = 500
innodb_buffer_pool_size = 2048M
innodb_write_io_threads = 4
innodb_read_io_threads = 4
innodb_thread_concurrency = 0
innodb_purge_threads = 1
innodb_flush_log_at_trx_commit = 2
innodb_log_buffer_size = 2M
innodb_log_file_size = 32M
innodb_log_files_in_group = 3
innodb_max_dirty_pages_pct = 90
innodb_lock_wait_timeout = 120

bulk_insert_buffer_size = 8M
myisam_sort_buffer_size = 64M
myisam_max_sort_file_size = 10G
myisam_repair_threads = 1

interactive_timeout = 28800
wait_timeout = 28800

[mysqldump]
quick
max_allowed_packet = 500M

[myisamchk]
key_buffer_size = 256M
sort_buffer_size = 8M
read_buffer = 4M
write_buffer = 4M

谢谢大家了！