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Administering Resource Management in Oracle® Solaris 11.4

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Updated: August 2018
 
 

Configuring Resource Controls and Attributes

The resource controls facility is configured through the project database. See About Projects and Tasks. Resource controls and other attributes are set in the final field of the project database entry. The values associated with each resource control are enclosed in parentheses, and appear as plain text separated by commas. The values in parentheses constitute an action clause. Each action clause is composed of a privilege level, a threshold value, and an action that is associated with the particular threshold. Each resource control can have multiple action clauses, which are also separated by commas.

The following entry defines a per-task lightweight process limit and a per-process maximum CPU time limit on a project entity. The process.max-cpu-time value would send a process a SIGTERM after the process ran for 1 hour, and a SIGKILL if the process continued to run for a total of 1 hour and 1 minute. See Figure 3, Table 3, Signals Available to Resource Control Values.

Typed as one line:
development:101:Developers:::task.max-lwps=(privileged,10,deny);
process.max-cpu-time=(basic,3600,signal=TERM),(priv,3660,signal=KILL)

Note -  On systems that have zones enabled, zone-wide resource controls are specified in the zone configuration using a slightly different format. See Setting Zone-Wide Resource Controls in Oracle Solaris Zones Configuration Resources for more information.

The rctladm command allows you to make runtime interrogations of and modifications to the resource controls facility, with global scope. The prctl command allows you to make runtime interrogations of and modifications to the resource controls facility, with local scope.

For more information, see Global and Local Actions on Resource Control Values and the rctladm(8) and prctl(1) man pages.


Note -  On a system with zones installed, you cannot use the rctladm command in a non-global zone to modify settings. You can use the rctladm command in a non-global zone to view the global logging state of each resource control.

Available Resource Controls

A list of the standard resource controls that are available in this release is shown in the following table.

The table describes the resource that is constrained by each control. The table also identifies the default units that are used by the project database for that resource. The default units are of two types:

  • Quantities represent a limited amount.

  • Indexes represent a maximum valid identifier.

Thus, project.cpu-shares resource control specifies the number of shares to which the project is entitled. The process.max-file-descriptor resource control specifies the highest file number that can be assigned to a process by the open system call.

Table 1  Standard Project, Task, and Process Resource Controls
Control Name
Description
Default Unit
process.max-address-space
Maximum amount of address space, as summed over segment sizes, that is available to this process.
Size (bytes)
process.max-core-size
Maximum size of a core file created by this process.
Size (bytes)
process.max-cpu-time
Maximum CPU time that is available to this process.
Time (seconds)
process.max-data-size
Maximum heap memory available to this process.
Size (bytes)
process.max-file-descriptor
Maximum file descriptor index available to this process.
Index (maximum file descriptor)
process.max-file-size
Maximum file offset available for writing by this process.
Size (bytes)
process.max-msg-messages
Maximum number of messages on a message queue (value copied from the resource control at msgget() time).
Quantity (number of messages)
process.max-msg-qbytes
Maximum number of bytes of messages on a message queue (value copied from the resource control at msgget() time).
Size (bytes)
process.max-port-events
Maximum allowable number of events per event port.
Quantity (number of events)
process.max-sem-nsems
Maximum number of semaphores allowed per semaphore set.
Quantity (semaphores per set)
process.max-sem-ops
Maximum number of semaphore operations allowed per semop call (value copied from the resource control at semget() time).
Quantity (number of operations)
process.max-stack-size
Maximum stack memory segment available to this process.
Size (bytes)
project.max-adi-metadata-memory
Total amount of memory for storing Silicon Secured Memory (SSM), also known as ADI, metadata of pages that might be written to backing store, expressed as a number of bytes.
Size (bytes)
project.cpu-cap
Absolute limit on the amount of CPU resources that can be consumed by a project. A value of 100 means 100% of one CPU as the project.cpu-cap setting. A value of 125 is 125%, because 100% corresponds to one full CPU on the system when using CPU caps.
Quantity (number of CPUs)
project.cpu-shares
Number of CPU shares granted to this project for use with the fair share scheduler (see FSS(4)).
Quantity (shares)
project.max-contracts
Maximum number of contracts allowed in this project.
Quantity (contracts)
project.max-locked-memory
Total amount of physical locked memory allowed.
If priv_proc_lock_memory is assigned to a user, consider setting this resource control as well to prevent that user from locking all memory.
Note that this resource control replaced project.max-device-locked-memory, which has been removed.
Size (bytes)
project.max-lwps
Maximum number of LWPs simultaneously available to this project.
Quantity (LWPs)
project.max-msg-ids
Maximum number of message queue IDs allowed for this project.
Quantity (message queue IDs)
project.max-port-ids
Maximum allowable number of event ports.
Quantity (number of event ports)
project.max-processes
Maximum number of process table slots simultaneously available to this project.
Note that because both normal processes and zombie processes take up process table slots, the max-processes control thus protects against zombies exhausting the process table. Because zombie processes do not have any LWPs by definition, the max-lwps control cannot protect against this possibility.
Quantity (process table slots)
project.max-sem-ids
Maximum number of semaphore IDs allowed for this project.
Quantity (semaphore IDs)
project.max-shm-ids
Maximum number of shared memory IDs allowed for this project.
Quantity (shared memory IDs)
project.max-shm-memory
Total amount of System V shared memory allowed for this project.
Size (bytes)
project.max-tasks
Maximum number of tasks allowable in this project.
Quantity (number of tasks)
task.max-cpu-time
Maximum CPU time that is available to this task's processes.
Time (seconds)
task.max-lwps
Maximum number of LWPs simultaneously available to this task's processes.
Quantity (LWPs)
task.max-processes
Maximum number of process table slots simultaneously available to this task's processes.
Quantity (process table slots)

You can display the default values for resource controls on a system that does not have any resource controls set or changed. Such a system contains no non-default entries in the /etc/system file or the project database. To display values, use the prctl command.

Zone-Wide Resource Controls

Zone-wide resource controls limit the total resource usage of all process entities within a zone. Zone-wide resource controls can also be set using global property names as described in Configurable Resource Types and Global Properties in Oracle Solaris Zones Configuration Resources.

Table 2  Zones Resource Controls
Control Name
Description
Default Unit
zone.cpu-cap
Absolute limit on the amount of CPU resources that can be consumed by a non-global zone.
A value of 100 means 100% of one CPU as the project.cpu-cap setting. A value of 125 is 125%, because 100% corresponds to one full CPU on the system when using CPU caps.
Quantity (number of CPUs)
zone.cpu-shares
Number of fair share scheduler (FSS) CPU shares for this zone.
Quantity (shares)
zone.max-adi-metadata-memory
Total amount of memory for storing Silicon Secured Memory (SSM) metadata of pages that may be written to backing store, expressed as a number of bytes. SSM is also known as ADI.
Size (bytes)
zone.max-lofi
Maximum number of lofi devices that can be created by a zone.
The value limits each zone's usage of the minor node namespace.
Quantity (number of lofi devices)
zone.max-locked-memory
Total amount of physical locked memory available to a zone.
When priv_proc_lock_memory is assigned to a zone, consider setting this resource control as well to prevent that zone from locking all memory.
Size (bytes)
zone.max-lwps
Maximum number of LWPs simultaneously available to this zone
Quantity (LWPs)
zone.max-msg-ids
Maximum number of message queue IDs allowed for this zone
Quantity (message queue IDs)
zone.max-processes
Maximum number of process table slots simultaneously available to this zone.
Because both normal processes and zombie processes take up process table slots, the max-processes control thus protects against zombies exhausting the process table. Because zombie processes do not have any LWPs by definition, the max-lwps control cannot protect against this possibility.
Quantity (process table slots)
zone.max-sem-ids
Maximum number of semaphore IDs allowed for this zone
Quantity (semaphore IDs)
zone.max-shm-ids
Maximum number of shared memory IDs allowed for this zone
Quantity (shared memory IDs)
zone.max-shm-memory
Total amount of System V shared memory allowed for this zone
Size (bytes)
zone.max-swap
Total amount of swap that can be consumed by user process address space mappings and tmpfs mounts for this zone.
Size (bytes)

For information about configuring zone-wide resource controls, see Configuring Resource Controls and Attributes and Setting Zone-Wide Resource Controls in Oracle Solaris Zones Configuration Resources.

Note that it is possible to apply a zone-wide resource control to the global zone.

Units Support

Global flags that identify resource control types are defined for all resource controls. The flags are used by the system to communicate basic type information to applications such as the prctl command. Applications use the information to determine the following:

  • The unit strings that are appropriate for each resource control

  • The correct scale to use when interpreting scaled values

The following global flags are available:

RCTL_GLOBAL_BYTES

Resource control type string: bytes

Modifier
Scale
B
1
KB
210
MB
220
GB
230
TB
240
PB
250
EB
260
RCTL_GLOBAL_SECONDS

Resource control type string: seconds

Modifier
Scale
s
1
Ks
103
Ms
106
Gs
109
Ts
1012
Ps
1015
Es
1018
RCTL_GLOBAL_COUNT

Resource control type string: count

Modifier
Scale
none
1
K
103
M
106
G
109
T
1012
P
1015
E
1018

Scaled values can be used with resource controls. The following example shows a scaled threshold value:

task.max-lwps=(priv,1K,deny)

Note -  Unit modifiers are accepted by the prctl, projadd, and projmod commands. You cannot use unit modifiers in the project database itself.

Resource Control Values and Privilege Levels

A threshold value on a resource control constitutes an enforcement point where local actions can be triggered or global actions, such as logging, can occur.

Each threshold value on a resource control must be associated with a privilege level. The privilege level must be one of the following three types.

  • Basic, which can be modified by the owner of the calling process

  • Privileged, which can be modified only by privileged (root) callers

  • System, which is fixed for the duration of the operating system instance

A resource control is guaranteed to have one system value, which is defined by the system, or resource provider. The system value represents how much of the resource the current implementation of the operating system is capable of providing.

Any number of privileged values can be defined, and only one basic value is allowed. Operations that are performed without specifying a privilege value are assigned a basic privilege by default.

The privilege level for a resource control value is defined in the privilege field of the resource control block as RCTL_BASIC, RCTL_PRIVILEGED, or RCTL_SYSTEM. See the setrctl(2) man page for more information. You can use the prctl command to modify values that are associated with basic and privileged levels.

Global and Local Actions on Resource Control Values

There are two categories of actions on resource control values: global and local.

Global Actions on Resource Control Values

Global actions apply to resource control values for every resource control on the system. You can use the rctladm command described in the rctladm(8) man page to perform the following actions:

  • Display the global state of active system resource controls

  • Set global logging actions

You can disable or enable the global logging action on resource controls. You can set the syslog action to a specific degree by assigning a severity level, syslog=level. The possible settings for level are as follows:

  • alert

  • crit

  • debug

  • emerg

  • err

  • info

  • notice

  • warning

By default, there is no global logging of resource control violations. The level n/a indicates resource controls on which no global action can be configured.

Local Actions on Resource Control Values

Local actions are taken on a process that attempts to exceed the control value. For each threshold value that is placed on a resource control, you can associate one or more actions. There are three types of local actions: deny, none, and signal=. These three actions are used as follows:

deny

You can deny resource requests for an amount that is greater than the threshold. For example, a task.max-lwps resource control with action deny causes a fork system call to fail if the new process would exceed the control value. See the fork(2) man page.

none

No action is taken on resource requests for an amount that is greater than the threshold. This action is useful for monitoring resource usage without affecting the progress of applications. You can also enable a global message that displays when the resource control is exceeded, although the process exceeding the threshold is not affected.

signal=

You can enable a global signal message action when the resource control is exceeded. A signal is sent to the process when the threshold value is exceeded. Additional signals are not sent if the process consumes additional resources. Available signals are listed in Figure 3, Table 3, Signals Available to Resource Control Values.

Not all of the actions can be applied to every resource control. For example, a process cannot exceed the number of CPU shares assigned to the project of which it is a member. Therefore, a deny action is not allowed on the project.cpu-shares resource control.

Due to implementation restrictions, the global properties of each control can restrict the range of available actions that can be set on the threshold value. (See the rctladm(8) man page.) A list of available signal actions is presented in the following table. For additional information about signals, see the signal(3HEAD) man page.

Table 3  Signals Available to Resource Control Values
Signal
Description
Notes
SIGABRT
Terminate the process.
SIGHUP
Send a hangup signal. Occurs when carrier drops on an open line. Signal sent to the process group that controls the terminal.
SIGKILL
Terminate the process and kill the program.
SIGSTOP
Stop the process. Job control signal.
SIGTERM
Terminate the process. Termination signal sent by software.
SIGXCPU
Terminate the process. CPU time limit exceeded.
Available only to resource controls with the RCTL_GLOBAL_CPUTIME property (process.max-cpu-time). See the rctlblk_set_value(3C) man page for more information.
SIGXFSZ
Terminate the process. File size limit exceeded.
Available only to resource controls with the RCTL_GLOBAL_FILE_SIZE property (process.max-file-size). See the rctlblk_set_value(3C) man page for more information.
SIGXRES
Resource control limit exceeded. Generated by resource control facility.

Resource Control Flags and Properties

Each resource control on the system has a certain set of associated properties. This set of properties is defined as a set of flags, which are associated with all controlled instances of that resource. Global flags cannot be modified, but the flags can be retrieved by using either rctladm or the getrctl system call.

Local flags define the default behavior and configuration for a specific threshold value of that resource control on a specific process or process collective. The local flags for one threshold value do not affect the behavior of other defined threshold values for the same resource control. However, the global flags affect the behavior for every value associated with a particular control. Local flags can be modified, within the constraints supplied by their corresponding global flags, by the prctl command or the setrctl system call. For more information, see the setrctl(2) man page.

For the complete list of local flags, global flags, and their definitions, see the rctlblk_set_value(3C) man page.

To determine system behavior when a threshold value for a particular resource control is reached, use the rctladm command to display the global flags for the resource control . For example, to display the values for the process.max-cpu-time resource control, type the following:

$ rctladm process.max-cpu-time
process.max-cpu-time  syslog=off  [ lowerable no-deny cpu-time inf seconds ]

The global flags indicate the following.

bytes

Unit of size for the resource control.

count

A count (integer) value for the resource control.

cpu-time

SIGXCPU is available to be sent when threshold values of this resource are reached.

deny

Always deny request for resource when threshold values are exceeded.

lowerable

Superuser privileges are not required to lower the privileged values for this control.

no-basic

Resource control values with the privilege type basic cannot be set. Only privileged resource control values are allowed.

no-deny

Even when threshold values are exceeded, access to the resource is never denied.

no-signal

A local signal action cannot be set on resource control values.

no-syslog

The global syslog message action may not be set for this resource control.

seconds

The time value for the resource control.

Use the prctl command to display local values and actions for the resource control.

$ prctl -n process.max-cpu-time $$
process 353939: -ksh
NAME    PRIVILEGE    VALUE    FLAG   ACTION              RECIPIENT
 process.max-cpu-time
         privileged   18.4Es    inf   signal=XCPU                 -
         system       18.4Es    inf   none 

The max (RCTL_LOCAL_MAXIMAL) flag is set for both threshold values, and the inf (RCTL_GLOBAL_INFINITE) flag is defined for this resource control. An inf value has an infinite quantity. The value is never enforced. Hence, as configured, both threshold quantities represent infinite values that are never exceeded.

Resource Control Enforcement

More than one resource control can exist on a resource. A resource control can exist at each containment level in the process model. If resource controls are active on the same resource at different container levels, the smallest container's control is enforced first. Thus, action is taken on process.max-cpu-time before task.max-cpu-time if both controls are encountered simultaneously.

Figure 3  Process Collectives, Container Relationships, and Their Resource Control Sets

image:Diagram shows enforcement of each resource control at its containment level.

Global Monitoring of Resource Control Events

Often, the resource consumption of processes is unknown. To get more information, try using the global resource control actions that are available with the rctladm command. Use rctladm to establish a syslog action on a resource control. Then, if any entity managed by that resource control encounters a threshold value, a system message is logged at the configured logging level. See Administering Resource Controls Tasks and the rctladm(8) man page for more information.