2015-02-14
Additional charts
Host zm08.stanford.edu: Total CPU
avg(user) = 3.17 avg(sys) = 0.40 avg(idle) = 94.07 avg(iowait) = 2.32 avg(nice) = 0.00 avg(irq) = 0.00 avg(softirq) = 0.03
Host zm08.stanford.edu: Individual CPU user time
avg(cpu0) = 9.66 avg(cpu1) = 9.76 avg(cpu2) = 3.45 avg(cpu3) = 3.31 avg(cpu4) = 2.19 avg(cpu5) = 3.03 avg(cpu6) = 1.31 avg(cpu7) = 1.35 avg(cpu8) = 0.87 avg(cpu9) = 2.53 avg(cpu10) = 0.75 avg(cpu11) = 2.30 avg(cpu12) = 4.23 avg(cpu13) = 3.22 avg(cpu14) = 9.17 avg(cpu15) = 2.54 avg(cpu16) = 7.96 avg(cpu17) = 2.04 avg(cpu18) = 0.91 avg(cpu19) = 2.40 avg(cpu20) = 0.63 avg(cpu21) = 1.06 avg(cpu22) = 0.53 avg(cpu23) = 0.83
Host zm08.stanford.edu: Individual CPU nice time
avg(cpu0) = 0.00 avg(cpu1) = 0.00 avg(cpu2) = 0.00 avg(cpu3) = 0.00 avg(cpu4) = 0.00 avg(cpu5) = 0.00 avg(cpu6) = 0.00 avg(cpu7) = 0.00 avg(cpu8) = 0.00 avg(cpu9) = 0.00 avg(cpu10) = 0.00 avg(cpu11) = 0.00 avg(cpu12) = 0.00 avg(cpu13) = 0.00 avg(cpu14) = 0.00 avg(cpu15) = 0.00 avg(cpu16) = 0.00 avg(cpu17) = 0.00 avg(cpu18) = 0.00 avg(cpu19) = 0.00 avg(cpu20) = 0.00 avg(cpu21) = 0.00 avg(cpu22) = 0.00 avg(cpu23) = 0.00
Host zm08.stanford.edu: Individual CPU sys time
avg(cpu0) = 0.90 avg(cpu1) = 0.98 avg(cpu2) = 0.49 avg(cpu3) = 0.53 avg(cpu4) = 0.33 avg(cpu5) = 0.42 avg(cpu6) = 0.22 avg(cpu7) = 0.24 avg(cpu8) = 0.16 avg(cpu9) = 0.27 avg(cpu10) = 0.13 avg(cpu11) = 0.27 avg(cpu12) = 0.49 avg(cpu13) = 0.45 avg(cpu14) = 1.17 avg(cpu15) = 0.58 avg(cpu16) = 0.56 avg(cpu17) = 0.37 avg(cpu18) = 0.17 avg(cpu19) = 0.30 avg(cpu20) = 0.14 avg(cpu21) = 0.19 avg(cpu22) = 0.12 avg(cpu23) = 0.16
Host zm08.stanford.edu: Individual CPU idle time
avg(cpu0) = 69.44 avg(cpu1) = 66.79 avg(cpu2) = 95.25 avg(cpu3) = 95.17 avg(cpu4) = 97.14 avg(cpu5) = 95.96 avg(cpu6) = 98.34 avg(cpu7) = 98.22 avg(cpu8) = 98.91 avg(cpu9) = 97.00 avg(cpu10) = 99.07 avg(cpu11) = 97.25 avg(cpu12) = 90.56 avg(cpu13) = 91.32 avg(cpu14) = 89.39 avg(cpu15) = 96.73 avg(cpu16) = 91.28 avg(cpu17) = 97.44 avg(cpu18) = 98.89 avg(cpu19) = 97.10 avg(cpu20) = 99.20 avg(cpu21) = 98.71 avg(cpu22) = 99.32 avg(cpu23) = 98.92
Host zm08.stanford.edu: Individual CPU iowait time
avg(cpu0) = 19.87 avg(cpu1) = 22.26 avg(cpu2) = 0.75 avg(cpu3) = 0.91 avg(cpu4) = 0.30 avg(cpu5) = 0.53 avg(cpu6) = 0.11 avg(cpu7) = 0.17 avg(cpu8) = 0.04 avg(cpu9) = 0.16 avg(cpu10) = 0.03 avg(cpu11) = 0.14 avg(cpu12) = 4.67 avg(cpu13) = 4.99 avg(cpu14) = 0.14 avg(cpu15) = 0.14 avg(cpu16) = 0.12 avg(cpu17) = 0.13 avg(cpu18) = 0.02 avg(cpu19) = 0.17 avg(cpu20) = 0.01 avg(cpu21) = 0.03 avg(cpu22) = 0.02 avg(cpu23) = 0.10
Host zm08.stanford.edu: Individual CPU irq time
avg(cpu0) = 0.00 avg(cpu1) = 0.00 avg(cpu2) = 0.00 avg(cpu3) = 0.00 avg(cpu4) = 0.00 avg(cpu5) = 0.00 avg(cpu6) = 0.00 avg(cpu7) = 0.00 avg(cpu8) = 0.00 avg(cpu9) = 0.00 avg(cpu10) = 0.00 avg(cpu11) = 0.00 avg(cpu12) = 0.00 avg(cpu13) = 0.00 avg(cpu14) = 0.00 avg(cpu15) = 0.00 avg(cpu16) = 0.00 avg(cpu17) = 0.00 avg(cpu18) = 0.00 avg(cpu19) = 0.00 avg(cpu20) = 0.00 avg(cpu21) = 0.00 avg(cpu22) = 0.00 avg(cpu23) = 0.00
Host zm08.stanford.edu: Individual CPU softirq time
avg(cpu0) = 0.13 avg(cpu1) = 0.18 avg(cpu2) = 0.05 avg(cpu3) = 0.06 avg(cpu4) = 0.02 avg(cpu5) = 0.04 avg(cpu6) = 0.01 avg(cpu7) = 0.01 avg(cpu8) = 0.01 avg(cpu9) = 0.02 avg(cpu10) = 0.00 avg(cpu11) = 0.02 avg(cpu12) = 0.04 avg(cpu13) = 0.01 avg(cpu14) = 0.11 avg(cpu15) = 0.00 avg(cpu16) = 0.06 avg(cpu17) = 0.00 avg(cpu18) = 0.00 avg(cpu19) = 0.02 avg(cpu20) = 0.00 avg(cpu21) = 0.00 avg(cpu22) = 0.00 avg(cpu23) = 0.00
Host zm08.stanford.edu: Process CPU
avg(mailbox) = 2.39 avg(mysql) = 0.32 avg(stats) = 0.00
Host zm08.stanford.edu: Process Total Memory
avg(mailbox) = 21338.66 avg(mysql) = 18153.30 avg(stats) = 0.00
Host zm08.stanford.edu: Process Resident Memory
avg(mailbox) = 8929.15 avg(mysql) = 17872.50 avg(stats) = 0.00
Host zm08.stanford.edu: Virtual Memory
avg(swapped) = 12.61 avg(free) = 2347.46 avg(active) = 38159.44 avg(inactive) = 22071.50 avg(page cache) = 29394.06
Host zm08.stanford.edu: Context Switches
avg(context switches) = 5353.88
Host zm08.stanford.edu: Run/Blocked Process Queue Size, Load Average
avg(processes waiting for run time) = 1.36 avg(processes waiting for io time) = 0.87 avg(load average (1 min)) = 1.82
Host zm08.stanford.edu: Disk Utilization (Top 10 avg)
avg(sdf) = 14.77 avg(dm-0) = 11.73 avg(sdg) = 9.38 avg(dm-2) = 24.38 avg(sdl) = 14.80 avg(sdh) = 13.73 avg(dm-4) = 18.31 avg(dm-3) = 3.08 avg(sdm) = 9.39 avg(sdn) = 13.75
Host zm08.stanford.edu: Disk Throughput: /dev/sde
avg(sde read) = 0.19 avg(sde write) = 0.00
Host zm08.stanford.edu: Disk Throughput: /dev/sdf
avg(sdf read) = 404.28 avg(sdf write) = 484.77
Host zm08.stanford.edu: Disk Throughput: /dev/sda
avg(sda read) = 0.19 avg(sda write) = 0.00
Host zm08.stanford.edu: Disk Throughput: /dev/sdk
avg(sdk read) = 17.04 avg(sdk write) = 30.57
Host zm08.stanford.edu: Disk Throughput: /dev/sdt
avg(sdt read) = 0.19 avg(sdt write) = 0.00
Host zm08.stanford.edu: Disk Throughput: /dev/sdq
avg(sdq read) = 0.19 avg(sdq write) = 0.00
Host zm08.stanford.edu: Disk Throughput: /dev/sdj
avg(sdj read) = 0.40 avg(sdj write) = 57.09
Host zm08.stanford.edu: Disk Throughput: /dev/dm-0
avg(dm-0 read) = 881.85 avg(dm-0 write) = 158.56
Host zm08.stanford.edu: Disk Throughput: /dev/sdg
avg(sdg read) = 441.28 avg(sdg write) = 79.46
Host zm08.stanford.edu: Disk Throughput: /dev/dm-1
avg(dm-1 read) = 0.42 avg(dm-1 write) = 113.09
Host zm08.stanford.edu: Disk Throughput: /dev/dm-2
avg(dm-2 read) = 808.29 avg(dm-2 write) = 969.54
Host zm08.stanford.edu: Disk Throughput: /dev/sdl
avg(sdl read) = 404.41 avg(sdl write) = 484.77
Host zm08.stanford.edu: Disk Throughput: /dev/sdc
avg(sdc read) = 0.19 avg(sdc write) = 0.00
Host zm08.stanford.edu: Disk Throughput: /dev/sdr
avg(sdr read) = 0.19 avg(sdr write) = 0.00
Host zm08.stanford.edu: Disk Throughput: /dev/sds
avg(sds read) = 0.19 avg(sds write) = 0.00
Host zm08.stanford.edu: Disk Throughput: /dev/sdi
avg(sdi read) = 310.95 avg(sdi write) = 330.48
Host zm08.stanford.edu: Disk Throughput: /dev/sdh
avg(sdh read) = 764.11 avg(sdh write) = 0.67
Host zm08.stanford.edu: Disk Throughput: /dev/dm-4
avg(dm-4 read) = 1528.50 avg(dm-4 write) = 1.35
Host zm08.stanford.edu: Disk Throughput: /dev/sdb
avg(sdb read) = 0.19 avg(sdb write) = 0.00
Host zm08.stanford.edu: Disk Throughput: /dev/dm-3
avg(dm-3 read) = 621.53 avg(dm-3 write) = 661.46
Host zm08.stanford.edu: Disk Throughput: /dev/sdm
avg(sdm read) = 440.97 avg(sdm write) = 79.10
Host zm08.stanford.edu: Disk Throughput: /dev/sdp
avg(sdp read) = 0.40 avg(sdp write) = 56.00
Host zm08.stanford.edu: Disk Throughput: /dev/sdn
avg(sdn read) = 764.78 avg(sdn write) = 0.68
Host zm08.stanford.edu: Disk Throughput: /dev/sdu
avg(sdu read) = 0.19 avg(sdu write) = 0.00
Host zm08.stanford.edu: Disk Throughput: /dev/sdd
avg(sdd read) = 0.19 avg(sdd write) = 0.00
Host zm08.stanford.edu: Disk Throughput: /dev/sdo
avg(sdo read) = 310.98 avg(sdo write) = 330.98
Host zm08.stanford.edu: Disk IOPs: /dev/sde
avg(sde read) = 0.05 avg(sde write) = 0.00
Host zm08.stanford.edu: Disk IOPs: /dev/sdf
avg(sdf read) = 26.24 avg(sdf write) = 19.81
Host zm08.stanford.edu: Disk IOPs: /dev/sda
avg(sda read) = 0.05 avg(sda write) = 0.00
Host zm08.stanford.edu: Disk IOPs: /dev/sdk
avg(sdk read) = 0.55 avg(sdk write) = 1.63
Host zm08.stanford.edu: Disk IOPs: /dev/sdt
avg(sdt read) = 0.05 avg(sdt write) = 0.00
Host zm08.stanford.edu: Disk IOPs: /dev/sdq
avg(sdq read) = 0.05 avg(sdq write) = 0.00
Host zm08.stanford.edu: Disk IOPs: /dev/sdj
avg(sdj read) = 0.10 avg(sdj write) = 0.44
Host zm08.stanford.edu: Disk IOPs: /dev/dm-0
avg(dm-0 read) = 61.62 avg(dm-0 write) = 15.29
Host zm08.stanford.edu: Disk IOPs: /dev/sdg
avg(sdg read) = 30.86 avg(sdg write) = 7.64
Host zm08.stanford.edu: Disk IOPs: /dev/dm-1
avg(dm-1 read) = 0.10 avg(dm-1 write) = 0.87
Host zm08.stanford.edu: Disk IOPs: /dev/dm-2
avg(dm-2 read) = 52.39 avg(dm-2 write) = 39.62
Host zm08.stanford.edu: Disk IOPs: /dev/sdl
avg(sdl read) = 26.25 avg(sdl write) = 19.81
Host zm08.stanford.edu: Disk IOPs: /dev/sdc
avg(sdc read) = 0.05 avg(sdc write) = 0.00
Host zm08.stanford.edu: Disk IOPs: /dev/sdr
avg(sdr read) = 0.05 avg(sdr write) = 0.00
Host zm08.stanford.edu: Disk IOPs: /dev/sds
avg(sds read) = 0.05 avg(sds write) = 0.00
Host zm08.stanford.edu: Disk IOPs: /dev/sdi
avg(sdi read) = 5.76 avg(sdi write) = 9.50
Host zm08.stanford.edu: Disk IOPs: /dev/sdh
avg(sdh read) = 16.07 avg(sdh write) = 0.04
Host zm08.stanford.edu: Disk IOPs: /dev/dm-4
avg(dm-4 read) = 32.05 avg(dm-4 write) = 0.09
Host zm08.stanford.edu: Disk IOPs: /dev/sdb
avg(sdb read) = 0.05 avg(sdb write) = 0.00
Host zm08.stanford.edu: Disk IOPs: /dev/dm-3
avg(dm-3 read) = 11.43 avg(dm-3 write) = 19.00
Host zm08.stanford.edu: Disk IOPs: /dev/sdm
avg(sdm read) = 30.86 avg(sdm write) = 7.65
Host zm08.stanford.edu: Disk IOPs: /dev/sdp
avg(sdp read) = 0.10 avg(sdp write) = 0.43
Host zm08.stanford.edu: Disk IOPs: /dev/sdn
avg(sdn read) = 16.07 avg(sdn write) = 0.04
Host zm08.stanford.edu: Disk IOPs: /dev/sdu
avg(sdu read) = 0.05 avg(sdu write) = 0.00
Host zm08.stanford.edu: Disk IOPs: /dev/sdd
avg(sdd read) = 0.05 avg(sdd write) = 0.00
Host zm08.stanford.edu: Disk IOPs: /dev/sdo
avg(sdo read) = 5.76 avg(sdo write) = 9.50
Host zm08.stanford.edu: Disk Usage
avg(/opt/zimbra/redo-mysql) = 42.99 avg(/usr/vice/cache) = 13.05 avg(/opt/zimbra/store) = 67.00 avg(/opt/zimbra) = 67.12 avg(/opt/zimbra/hsm1) = 91.00 avg(/) = 8.01 avg(/opt/zimbra/redolog) = 15.40
Host zm08.stanford.edu: Open file descriptor count
avg(total system file descriptors open) = 6663.06 avg(mailboxd file descriptors open) = 3335.91
Host zm08.stanford.edu: Process CPU Time (Top 10 avg)
avg(updatedb) = 23.85 avg(java) = 2053.58 avg(gzip) = 2401.05 avg(mysqld) = 237.48 avg(perl) = 20.89 avg(mysqldump) = 134.12 avg(zmmailboxd) = 1722.75 avg(rm) = 22.00 avg(horsewatcher-fe) = 22.69 avg(zmcompresslogs) = 1177.86
Host zm08.stanford.edu: SOAP: Invocation Count: Summary (Top 10 max)
max(MsgActionRequest.move) = 36.00 max(SearchRequest) = 57.00 max(MsgActionRequest.delete) = 185.00 max(NoOpRequest) = 72.00 max(GetInfoRequest) = 34.00 max(WaitSetRequest) = 32.00 max(GetFolderRequest) = 187.00 max(SyncRequest) = 50.00 max(AuthRequest) = 34.00 max(GetAppointmentRequest) = 44.00
Host zm08.stanford.edu: SOAP: Average Call Duration: Summary (Top 10 avg)
avg(SendMsgRequest) = 557.26 avg(DeleteAccountRequest) = 6617.75 avg(BackupQueryRequest) = 586.60 avg(GetAggregateQuotaUsageOnServerRequest) = 3117.00 avg(GetFreeBusyRequest) = 271.85 avg(BrowseRequest) = 542.50 avg(SendInviteReplyRequest) = 1099.50 avg(AutoCompleteRequest) = 271.54 avg(FolderActionRequest.empty) = 305.08 avg(GetQuotaUsageRequest) = 4081.00
Host zm08.stanford.edu: MySQL: InnoDB Buffer Pool Pages
avg(pages read) = 340192561.96 avg(pages written) = 125211232.85
Host zm08.stanford.edu: MySQL: InnoDB Buffer Pool Hit Rate
avg(buffer pool hit rate) = 999.07
Host zm08.stanford.edu: MySQL: Database Connections In Use
avg(connections in use) = 0.30
Host zm08.stanford.edu: MySQL: Tables Open/Opened
avg(open_tables) = 1189.60 avg(opened_tables (cumulative)) = 415724.05
Host zm08.stanford.edu: MySQL: Total Slow Queries Count
avg(slow queries (cumulative)) = 1321542.62
Host zm08.stanford.edu: Mailboxd: Connection Pool Get Latency
avg(mysql) = 0.19 avg(ldap) = 0.01
Host zm08.stanford.edu: Mailboxd: Lucene IO
avg(Index writes) = 37.36 avg(Index reads) = 116.16
Host zm08.stanford.edu: Mailboxd: LMTP Delivery Throughput
avg(received) = 47.55 avg(delivered) = 56.55
Host zm08.stanford.edu: Mailboxd: LMTP Delivery Rate
avg(received msgs) = 0.33 avg(delivered msgs) = 0.37 avg(received x rcpts) = 0.38
Host zm08.stanford.edu: Mailboxd: Mailbox Add Rate (Delivery Rate)
avg(mailbox add rate) = 0.45
Host zm08.stanford.edu: Mailboxd: Mailbox Add Latency (Delivery Speed)
avg(mailbox add latency) = 79.02
Host zm08.stanford.edu: Mailboxd: Request Rate by Client Protocol
avg(SOAP) = 3.12 avg(IMAP) = 45.82 avg(POP) = 1.87
Host zm08.stanford.edu: Mailboxd: Response Time by Client Protocol
avg(SOAP) = 289.36 avg(IMAP) = 24.25 avg(POP) = 61.88
Host zm08.stanford.edu: Mailboxd: Active Connections by Client Protocol
avg(IMAP) = 136.14 avg(IMAP SSL) = 472.22 avg(POP) = 0.01 avg(POP SSL) = 1.04 avg(SOAP sessions) = 132.87
Host zm08.stanford.edu: Mailboxd: Mailbox Get Count
avg(mailbox get count) = 2495.04
Host zm08.stanford.edu: Mailboxd: Mailbox Get Latency
avg(mailbox get latency) = 0.00
Host zm08.stanford.edu: Mailboxd: Mailbox Cache Hit Rate
avg(mailbox cache hit rate) = 99.99
Host zm08.stanford.edu: Mailboxd: Mailbox Item/Blob Cache Hit Rate
avg(msg blob cache) = 47.24 avg(item metadata cache) = 34.21
Host zm08.stanford.edu: Mailboxd: Minor Garbage Collection Time
avg(minor GC time) = 0.27
Host zm08.stanford.edu: Mailboxd: Major Garbage Collection Time
avg(major GC time) = 0.02
Host zm08.stanford.edu: Mailboxd: Minor Garbage Collection Count
avg(minor GC count) = 6.91
Host zm08.stanford.edu: Mailboxd: Major Garbage Collection Count
avg(major GC count) = 0.01
Host zm08.stanford.edu: Mailboxd: JVM Heap Used
avg(total) = 4737.22 avg(PS Old Gen) = 0.00 avg(CMS Old Gen) = 3857.74 avg(Tenured Gen) = 0.00 avg(Train Gen) = 0.00 avg(PS Eden Space) = 0.00 avg(PS Survivor Space) = 0.00 avg(Par Eden Space) = 806.51 avg(Par Survivor Space) = 72.97 avg(Eden Space) = 0.00 avg(Survivor Space) = 0.00
Host zm08.stanford.edu: Mailboxd: JVM Heap Free
avg(total free) = 3090.09 avg(PS Old Gen free) = 0.00 avg(CMS Old Gen free) = 2163.26 avg(Tenured Gen free) = 0.00 avg(Train Gen free) = 0.00 avg(PS Eden Space free) = 0.00 avg(PS Survivor Space free) = 0.00 avg(Par Eden Space free) = 799.11 avg(Par Survivor Space free) = 127.72 avg(Eden Space free) = 0.00 avg(Survivor Space free) = 0.00
Host zm08.stanford.edu: Mailboxd: JVM Permanent Generation and Code Cache
avg(PS Perm Gen) = 0.00 avg(Perm Gen) = 0.00 avg(CMS Perm Gen) = 142.22 avg(Code Cache) = 36.01 avg(Perm Gen [shared-ro]) = 0.00 avg(Perm Gen [shared-rw]) = 0.00 avg(PS Perm Gen free) = 0.00 avg(Perm Gen free) = 0.00 avg(CMS Perm Gen free) = 110.16 avg(Code Cache free) = 10.55 avg(Perm Gen [shared-ro] free) = 0.00 avg(Perm Gen [shared-rw] free) = 0.00
Host zm08.stanford.edu: convertd: CPU time used
avg(total cputime) = 0.05 avg(user time) = 0.05 avg(system time) = 0.00
Host zm08.stanford.edu: convertd: Resident Memory
avg(convertd rss) = 163.10
Host zm08.stanford.edu: convertd: Processes and Threads
avg(processes) = 5.56 avg(threads) = 5.56
No data available for the following charts:
Host zm08.stanford.edu: Swap Activity
Host zm08.stanford.edu: Disk Throughput: /dev/dm-7
Host zm08.stanford.edu: Disk Throughput: /dev/sdx
Host zm08.stanford.edu: Disk Throughput: /dev/sdab
Host zm08.stanford.edu: Disk Throughput: /dev/sdaa
Host zm08.stanford.edu: Disk Throughput: /dev/sdad
Host zm08.stanford.edu: Disk Throughput: /dev/sdag
Host zm08.stanford.edu: Disk Throughput: /dev/sdaf
Host zm08.stanford.edu: Disk Throughput: /dev/sdy
Host zm08.stanford.edu: Disk Throughput: /dev/sdv
Host zm08.stanford.edu: Disk Throughput: /dev/sdac
Host zm08.stanford.edu: Disk Throughput: /dev/dm-5
Host zm08.stanford.edu: Disk Throughput: /dev/sdw
Host zm08.stanford.edu: Disk Throughput: /dev/sdae
Host zm08.stanford.edu: Disk Throughput: /dev/dm-6
Host zm08.stanford.edu: Disk Throughput: /dev/sdz
Host zm08.stanford.edu: Disk IOPs: /dev/dm-7
Host zm08.stanford.edu: Disk IOPs: /dev/sdx
Host zm08.stanford.edu: Disk IOPs: /dev/sdab
Host zm08.stanford.edu: Disk IOPs: /dev/sdaa
Host zm08.stanford.edu: Disk IOPs: /dev/sdad
Host zm08.stanford.edu: Disk IOPs: /dev/sdag
Host zm08.stanford.edu: Disk IOPs: /dev/sdaf
Host zm08.stanford.edu: Disk IOPs: /dev/sdy
Host zm08.stanford.edu: Disk IOPs: /dev/sdv
Host zm08.stanford.edu: Disk IOPs: /dev/sdac
Host zm08.stanford.edu: Disk IOPs: /dev/dm-5
Host zm08.stanford.edu: Disk IOPs: /dev/sdw
Host zm08.stanford.edu: Disk IOPs: /dev/sdae
Host zm08.stanford.edu: Disk IOPs: /dev/dm-6
Host zm08.stanford.edu: Disk IOPs: /dev/sdz
Host zm08.stanford.edu: Mailboxd: Dirty Lucene Index Writers
Host zm08.stanford.edu: Mailboxd: Lucene IndexWriterCache Hitrate
Host zm08.stanford.edu: nginx: CPU time used
Host zm08.stanford.edu: nginx: Resident Memory
Host zm08.stanford.edu: nginx: Processes and Threads