一、Cacti日志出现大量错误
最近查看Cacti日志，出现大量红色告警，并且每五分钟出现1次，虽然不影响流量的查看，但是肯定会有问题。
错误日志如下
ERROR: A DB Exec Failed!, Error:'145', SQL:"INSERT INTO `cacti`.`syslog_hosts` (host) (SELECT DISTINCT host FROM `cacti`.`syslog_incoming`) ON DUPLICATE KEY UPDATE host=VALUES(host), last_updated=NOW()'
RROR: A DB Exec Failed!, Error:'145', SQL:"DELETE FROM `cacti`.`syslog_statistics` WHERE insert_time<
ERROR: A DB Exec Failed!, Error:'145', SQL:"INSERT INTO `cacti`.`syslog` (logtime, priority_id, facility_id, host_id, message) SELECT TIMESTAMP(`date`, `time`), priority_id, facility_id, host_id, message FROM (SELECT date, time, priority_id, facility_id, host_id, message FROM syslog_incoming AS si INNER JOIN syslog_facilities AS sf ON sf.facility=si.facility INNER JOIN syslog_priorities AS sp ON sp.priority=si.priority INNER JOIN syslog_hosts AS sh ON sh.host=si.host WHERE status=5) AS merge'
错误信息显示：
数据库中已经存在这台主机，再插入就失败了。
解决办法：
1、登入后台服务器，进入数据库
#mysql（我的后台数据库没有密码，直接进入）
2、查看数据库
mysql>show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| cacti |
| mysql |
+--------------------+
4 rows in set (0.00 sec)
3、进入cacti表
mysql> use cacti
4、显示数据库中的表
mysql> show tables；
+---------------------------------------+
| Tables_in_cacti |
+---------------------------------------+
| cdef |
| cdef_items |
| colors |
| data_input |
| data_input_data |
| data_input_fields |
| data_local |
| data_template |
| data_template_data |
| data_template_data_rra |
| data_template_rrd |
| graph_local |
| graph_template_input |
| graph_template_input_defs |
| graph_templates |
| graph_templates_gprint |
| graph_templates_graph |
| graph_templates_item |
| graph_tree |
| graph_tree_items |
| host |
| host_graph |
| host_snmp_cache |
| host_snmp_query |
| host_template |
| host_template_graph |
| host_template_snmp_query |
| plugin_aggregate_color_template_items |
| plugin_aggregate_color_templates |
| plugin_config |
| plugin_db_changes |
| plugin_hooks |
| plugin_realms |
| plugin_thold_contacts |
| plugin_thold_log |
| plugin_thold_template_contact |
| plugin_thold_threshold_contact |
| poller |
| poller_command |
| poller_item |
| poller_output |
| poller_output_rt |
| poller_reindex |
| poller_time |
| rra |
| rra_cf |
| settings |
| settings_graphs |
| settings_tree |
| snmp_query |
| snmp_query_graph |
| snmp_query_graph_rrd |
| snmp_query_graph_rrd_sv |
| snmp_query_graph_sv |
| syslog |
| syslog_alarm_log |
| syslog_alert |
| syslog_facilities |
| syslog_host_facilities |
| syslog_hosts |
| syslog_incoming |
| syslog_logs |
| syslog_priorities |
| syslog_remove |
| syslog_removed |
| syslog_reports |
| syslog_statistics |
| thold_data |
| thold_template |
| user_auth |
| user_auth_perms |
| user_auth_realm |
| user_log |
| version |
| weathermap_auth |
| weathermap_data |
| weathermap_groups |
| weathermap_maps |
| weathermap_settings |
+---------------------------------------+
79 rows in set (0.00 sec)
5、访问有问题的表
mysql> describe syslog_hosts;
ERROR 145 (HY000): Table './cacti/syslog_hosts' is marked as crashed and should be repaired
提示该表损坏需要修复。
6、修复数据库中的所有表
#mysqlcheck -A -o -r -p
7、修复完成后，再次进入数据库访问有错误的表
mysql> describe syslog_hosts;
+--------------+------------------+------+-----+-------------------+-----------------------------+
| Field | Type | Null | Key | Default | Extra |
+--------------+------------------+------+-----+-------------------+-----------------------------+
| host_id | int(10) unsigned | NO | MUL | NULL | auto_increment |
| host | varchar(128) | NO | PRI | NULL | |
| last_updated | timestamp | NO | MUL | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP |
+--------------+------------------+------+-----+-------------------+-----------------------------+
3 rows in set (0.00 sec)
可以正常访问了，错误日志也不在出现了
二、Cacti不出图
错误日志如下：
1、CMDPHP: Poller[0] ERROR: SQL Assoc Failed!, Error:'1017'
2、ERROR 1017 (HY000): Can't find file: 'poller_output' (errno: 2)
3、CMDPHP: Poller[0] ERROR: A DB Exec Failed!, Error:'1062'
按照1、2、3的顺序依次出现了以上三个错误(Cacti Log中截取的)，其中第二项错误是在MySQL中执行select count(*) from poller_output;时出现的。重新启动Apache、MySQL、snmp等进程均未能解决问题，在网上查找资料得知是Cacti数据库的问题。
问题原因：
Cacti数据库的poller_output表出现问题。
解决办法：
进入MySQL后执行truncate table poller_output;清空poller_output表后 Cacti恢复正常。
常见不出图或有图无数据
解决办法之二
登录CactiEZ中文版V10，点击“工具”菜单中的“系统工具”，然后点击“重建采集器缓存”。几分钟之后再查看是否正常，该办法能解决大多数问题。