场景:领导电话通知,我们的主站宕机了,到家后从另外一台机器上ssh一直处于等待状态,开始怀疑机器的负载比较高,后查看监控机器,发现网卡.cpu.nginx连接数.....通通都没有数据了,显然不是负载高度问题了,应该是机器死机了,立刻通过ipmi重启机器重启机器后,机器正常!其实这个机器都正常运行大半年了,没啥问题! 查询/var/log/messages,发现大量的信息如下: 点击(此处)折叠或打开 Mar 12 11:15:04 hy1 kernel: php-fpm: page alloc…

关键词:warn_alloc().__GFP_XXX.order.CMA等等. 在内存申请的时候经常会遇到类似“ xxx: page allocation failure: order:10...”类型的问题,这是warn_alloc()的输出. warn_alloc()被如下函数调用:__alloc_pages_slowpath().__vmalloc_area_node().__vmalloc_node_range. 下面分三部分了解这种问题的来龙去脉: 什么情况会导致warn_alloc(…

Hello,大家下午好. 近几天的项目有点赶,所以耽误了更新.现在给大家分享下,在安装mongodb的过程中,遇到的故障一则.其实很小白的问题,当时遇到这个问题的时候比较心慌,浪费了很多时间,跟大家分享下解决的思路吧. 先描述下我的环境,请参照前一篇博客,利用脚本初始化出4个节点(由于实验原因,我使用了单台的服务器). 首先我们启动这四个初始化节点.(具体的文件配置,请参照前文,初始化的内容,这里仅用/etc/mongodb.conf为例) [root@1]# cat /etc/mongodb.…

up vote 8 down vote accepted "Allocation Failure" is a cause of GC cycle to kick. "Allocation Failure" means what no more space left in Eden to allocate object. So, it is normal cause of young GC. Older JVM were not printing GC cause f…

话说那天正在向mongodb中写入数据,突然就蹦出了 new file allocation failure ,以为是数据有错误,就检查了一番,可没问题啊,看着像是mongo自己的问题,于是百度了一番,竟然是mongodb把磁盘写满了,以至于无法再分配新的磁盘空间存储数据了.…

The prioritization of large memory page mapping is a function of the access bits in the L1 page table. In a first phase of operation, the number of set access bits in each of the L1 page tables is counted periodically and a current count value is cal…

  All of the physical pages in the system are described by the mem_map  data structure which is a list of mem_map_t    typedef struct page { // these must be first (free area handling) struct page        *next;struct page        *prev;struct inode   …

Linux TCP Performance Tuning News Linux Performance Tuning Recommended Books Recommended Links Linux performance bottlenecks Kernel parameters tuning on Linux Performance Monitoring tcpdump iptraf netstat ntop nfsstat lsof vmstat Disk subsystem tunin…

1. min_free_kbytes 先看官方解释: This is used to force the Linux VM to keep a minimum number of kilobytes free. The VM uses this number to compute a watermark[WMARK_MIN] value for each lowmem zone in the system. Each lowmem zone gets a number of reserved f…

看到一个比较详细的分析wifi断开的文章.收藏一下. 原文: http://blog.csdn.net/chi_wy/article/details/50963279 原因1 ．从Log分析来看,这个是由于Dhcp request fail 导致最终disconnect . Log 分析如下: 16:53:31.659 958 6525 D NetUtils: dhcp_do_request failed : wlan0 (renew) 08-26 16:53:31.659 958 6525 E…