| Chuck Lever | 34e8f92 | 2008-06-12 12:32:25 -0400 | [diff] [blame] | 1 | /* |
| 2 | * User-space visible declarations for NFS client per-mount |
| 3 | * point statistics |
| 4 | * |
| 5 | * Copyright (C) 2005, 2006 Chuck Lever <cel@netapp.com> |
| 6 | * |
| 7 | * NFS client per-mount statistics provide information about the |
| 8 | * health of the NFS client and the health of each NFS mount point. |
| 9 | * Generally these are not for detailed problem diagnosis, but |
| 10 | * simply to indicate that there is a problem. |
| 11 | * |
| 12 | * These counters are not meant to be human-readable, but are meant |
| 13 | * to be integrated into system monitoring tools such as "sar" and |
| 14 | * "iostat". As such, the counters are sampled by the tools over |
| 15 | * time, and are never zeroed after a file system is mounted. |
| 16 | * Moving averages can be computed by the tools by taking the |
| 17 | * difference between two instantaneous samples and dividing that |
| 18 | * by the time between the samples. |
| 19 | */ |
| 20 | |
| 21 | #ifndef _LINUX_NFS_IOSTAT |
| 22 | #define _LINUX_NFS_IOSTAT |
| 23 | |
| 24 | #define NFS_IOSTAT_VERS "1.0" |
| 25 | |
| 26 | /* |
| 27 | * NFS byte counters |
| 28 | * |
| 29 | * 1. SERVER - the number of payload bytes read from or written |
| 30 | * to the server by the NFS client via an NFS READ or WRITE |
| 31 | * request. |
| 32 | * |
| 33 | * 2. NORMAL - the number of bytes read or written by applications |
| 34 | * via the read(2) and write(2) system call interfaces. |
| 35 | * |
| 36 | * 3. DIRECT - the number of bytes read or written from files |
| 37 | * opened with the O_DIRECT flag. |
| 38 | * |
| 39 | * These counters give a view of the data throughput into and out |
| 40 | * of the NFS client. Comparing the number of bytes requested by |
| 41 | * an application with the number of bytes the client requests from |
| 42 | * the server can provide an indication of client efficiency |
| 43 | * (per-op, cache hits, etc). |
| 44 | * |
| 45 | * These counters can also help characterize which access methods |
| 46 | * are in use. DIRECT by itself shows whether there is any O_DIRECT |
| 47 | * traffic. NORMAL + DIRECT shows how much data is going through |
| 48 | * the system call interface. A large amount of SERVER traffic |
| 49 | * without much NORMAL or DIRECT traffic shows that applications |
| 50 | * are using mapped files. |
| 51 | * |
| 52 | * NFS page counters |
| 53 | * |
| 54 | * These count the number of pages read or written via nfs_readpage(), |
| 55 | * nfs_readpages(), or their write equivalents. |
| 56 | * |
| 57 | * NB: When adding new byte counters, please include the measured |
| 58 | * units in the name of each byte counter to help users of this |
| 59 | * interface determine what exactly is being counted. |
| 60 | */ |
| 61 | enum nfs_stat_bytecounters { |
| 62 | NFSIOS_NORMALREADBYTES = 0, |
| 63 | NFSIOS_NORMALWRITTENBYTES, |
| 64 | NFSIOS_DIRECTREADBYTES, |
| 65 | NFSIOS_DIRECTWRITTENBYTES, |
| 66 | NFSIOS_SERVERREADBYTES, |
| 67 | NFSIOS_SERVERWRITTENBYTES, |
| 68 | NFSIOS_READPAGES, |
| 69 | NFSIOS_WRITEPAGES, |
| 70 | __NFSIOS_BYTESMAX, |
| 71 | }; |
| 72 | |
| 73 | /* |
| 74 | * NFS event counters |
| 75 | * |
| 76 | * These counters provide a low-overhead way of monitoring client |
| 77 | * activity without enabling NFS trace debugging. The counters |
| 78 | * show the rate at which VFS requests are made, and how often the |
| 79 | * client invalidates its data and attribute caches. This allows |
| 80 | * system administrators to monitor such things as how close-to-open |
| 81 | * is working, and answer questions such as "why are there so many |
| 82 | * GETATTR requests on the wire?" |
| 83 | * |
| 84 | * They also count anamolous events such as short reads and writes, |
| 85 | * silly renames due to close-after-delete, and operations that |
| 86 | * change the size of a file (such operations can often be the |
| 87 | * source of data corruption if applications aren't using file |
| 88 | * locking properly). |
| 89 | */ |
| 90 | enum nfs_stat_eventcounters { |
| 91 | NFSIOS_INODEREVALIDATE = 0, |
| 92 | NFSIOS_DENTRYREVALIDATE, |
| 93 | NFSIOS_DATAINVALIDATE, |
| 94 | NFSIOS_ATTRINVALIDATE, |
| 95 | NFSIOS_VFSOPEN, |
| 96 | NFSIOS_VFSLOOKUP, |
| 97 | NFSIOS_VFSACCESS, |
| 98 | NFSIOS_VFSUPDATEPAGE, |
| 99 | NFSIOS_VFSREADPAGE, |
| 100 | NFSIOS_VFSREADPAGES, |
| 101 | NFSIOS_VFSWRITEPAGE, |
| 102 | NFSIOS_VFSWRITEPAGES, |
| 103 | NFSIOS_VFSGETDENTS, |
| 104 | NFSIOS_VFSSETATTR, |
| 105 | NFSIOS_VFSFLUSH, |
| 106 | NFSIOS_VFSFSYNC, |
| 107 | NFSIOS_VFSLOCK, |
| 108 | NFSIOS_VFSRELEASE, |
| 109 | NFSIOS_CONGESTIONWAIT, |
| 110 | NFSIOS_SETATTRTRUNC, |
| 111 | NFSIOS_EXTENDWRITE, |
| 112 | NFSIOS_SILLYRENAME, |
| 113 | NFSIOS_SHORTREAD, |
| 114 | NFSIOS_SHORTWRITE, |
| 115 | NFSIOS_DELAY, |
| 116 | __NFSIOS_COUNTSMAX, |
| 117 | }; |
| 118 | |
| 119 | #endif /* _LINUX_NFS_IOSTAT */ |