MS Exchange

Plugin: go.d.plugin Module: windows

Overview

This collector monitors the performance of Windows machines, collects both host metrics and metrics from various Windows applications (e.g. Active Directory, MSSQL).

It collect metrics by periodically sending HTTP requests to Prometheus exporter for Windows machines, a native Windows agent running on each host.

This collector is supported on all platforms.

This collector supports collecting metrics from multiple instances of this integration, including remote instances.

Default Behavior

Auto-Detection

It detects Windows exporter instances running on localhost (requires using Netdata MSI installer).

Using the Netdata MSI installer is recommended for testing purposes only. For production use, you need to install Netdata on a Linux host and configure it to collect metrics remotely.

Limits

The default configuration for this integration does not impose any limits on data collection.

Performance Impact

Data collection affects the CPU usage of the Windows host. CPU usage depends on the frequency of data collection and the enabled collectors.

Metrics

Metrics grouped by scope.

The scope defines the instance that the metric belongs to. An instance is uniquely identified by a set of labels.

The collected set of metrics depends on the enabled collectors.

Supported collectors:

• cpu
• iis
• memory
• net
• logical_disk
• os
• system
• logon
• tcp
• thermalzone
• process
• service
• mssql
• ad
• adcs
• adfs
• netframework_clrexceptions
• netframework_clrinterop
• netframework_clrjit
• netframework_clrloading
• netframework_clrlocksandthreads
• netframework_clrmemory
• netframework_clrremoting
• exchange
• hyperv

Per Active Directory instance

These metrics refer to the entire monitored host.

This scope has no labels.

Metrics:

Metric	Dimensions	Unit
windows.cpu_utilization_total	dpc, user, privileged, interrupt	percentage
windows.memory_utilization	available, used	bytes
windows.memory_page_faults	page_faults	events/s
windows.memory_swap_utilization	available, used	bytes
windows.memory_swap_operations	read, write	operations/s
windows.memory_swap_pages	read, written	pages/s
windows.memory_cached	cached	KiB
windows.memory_cache_faults	cache_faults	events/s
windows.memory_system_pool	paged, non-paged	bytes
windows.tcp_conns_established	ipv4, ipv6	connections
windows.tcp_conns_active	ipv4, ipv6	connections/s
windows.tcp_conns_passive	ipv4, ipv6	connections/s
windows.tcp_conns_failures	ipv4, ipv6	failures/s
windows.tcp_conns_resets	ipv4, ipv6	resets/s
windows.tcp_segments_received	ipv4, ipv6	segments/s
windows.tcp_segments_sent	ipv4, ipv6	segments/s
windows.tcp_segments_retransmitted	ipv4, ipv6	segments/s
windows.os_processes	processes	number
windows.os_users	users	users
windows.os_visible_memory_usage	free, used	bytes
windows.os_paging_files_usage	free, used	bytes
windows.system_threads	threads	number
windows.system_uptime	time	seconds
windows.logon_type_sessions	system, interactive, network, batch, service, proxy, unlock, network_clear_text, new_credentials, remote_interactive, cached_interactive, cached_remote_interactive, cached_unlock	seconds
windows.processes_cpu_utilization	a dimension per process	percentage
windows.processes_handles	a dimension per process	handles
windows.processes_io_bytes	a dimension per process	bytes/s
windows.processes_io_operations	a dimension per process	operations/s
windows.processes_page_faults	a dimension per process	pgfaults/s
windows.processes_page_file_bytes	a dimension per process	bytes
windows.processes_pool_bytes	a dimension per process	bytes
windows.processes_threads	a dimension per process	threads
ad.database_operations	add, delete, modify, recycle	operations/s
ad.directory_operations	read, write, search	operations/s
ad.name_cache_lookups	lookups	lookups/s
ad.name_cache_hits	hits	hits/s
ad.atq_average_request_latency	time	seconds
ad.atq_outstanding_requests	outstanding	requests
ad.dra_replication_intersite_compressed_traffic	inbound, outbound	bytes/s
ad.dra_replication_intrasite_compressed_traffic	inbound, outbound	bytes/s
ad.dra_replication_sync_objects_remaining	inbound, outbound	objects
ad.dra_replication_objects_filtered	inbound, outbound	objects/s
ad.dra_replication_properties_updated	inbound, outbound	properties/s
ad.dra_replication_properties_filtered	inbound, outbound	properties/s
ad.dra_replication_pending_syncs	pending	syncs
ad.dra_replication_sync_requests	requests	requests/s
ad.ds_threads	in_use	threads
ad.ldap_last_bind_time	last_bind	seconds
ad.binds	binds	binds/s
ad.ldap_searches	searches	searches/s
adfs.ad_login_connection_failures	connection	failures/s
adfs.certificate_authentications	authentications	authentications/s
adfs.db_artifact_failures	connection	failures/s
adfs.db_artifact_query_time_seconds	query_time	seconds/s
adfs.db_config_failures	connection	failures/s
adfs.db_config_query_time_seconds	query_time	seconds/s
adfs.device_authentications	authentications	authentications/s
adfs.external_authentications	success, failure	authentications/s
adfs.federated_authentications	authentications	authentications/s
adfs.federation_metadata_requests	requests	requests/s
adfs.oauth_authorization_requests	requests	requests/s
adfs.oauth_client_authentications	success, failure	authentications/s
adfs.oauth_client_credentials_requests	success, failure	requests/s
adfs.oauth_client_privkey_jwt_authentications	success, failure	authentications/s
adfs.oauth_client_secret_basic_authentications	success, failure	authentications/s
adfs.oauth_client_secret_post_authentications	success, failure	authentications/s
adfs.oauth_client_windows_authentications	success, failure	authentications/s
adfs.oauth_logon_certificate_requests	success, failure	requests/s
adfs.oauth_password_grant_requests	success, failure	requests/s
adfs.oauth_token_requests_success	success	requests/s
adfs.passive_requests	passive	requests/s
adfs.passport_authentications	passport	authentications/s
adfs.password_change_requests	success, failure	requests/s
adfs.samlp_token_requests_success	success	requests/s
adfs.sso_authentications	success, failure	authentications/s
adfs.token_requests	requests	requests/s
adfs.userpassword_authentications	success, failure	authentications/s
adfs.windows_integrated_authentications	authentications	authentications/s
adfs.wsfed_token_requests_success	success	requests/s
adfs.wstrust_token_requests_success	success	requests/s
exchange.activesync_ping_cmds_pending	pending	commands
exchange.activesync_requests	received	requests/s
exchange.activesync_sync_cmds	processed	commands/s
exchange.autodiscover_requests	processed	requests/s
exchange.avail_service_requests	serviced	requests/s
exchange.owa_current_unique_users	logged-in	users
exchange.owa_requests_total	handled	requests/s
exchange.rpc_active_user_count	active	users
exchange.rpc_avg_latency	latency	seconds
exchange.rpc_connection_count	connections	connections
exchange.rpc_operations	operations	operations/s
exchange.rpc_requests	processed	requests
exchange.rpc_user_count	users	users
exchange.transport_queues_active_mail_box_delivery	low, high, none, normal	messages/s
exchange.transport_queues_external_active_remote_delivery	low, high, none, normal	messages/s
exchange.transport_queues_external_largest_delivery	low, high, none, normal	messages/s
exchange.transport_queues_internal_active_remote_delivery	low, high, none, normal	messages/s
exchange.transport_queues_internal_largest_delivery	low, high, none, normal	messages/s
exchange.transport_queues_retry_mailbox_delivery	low, high, none, normal	messages/s
exchange.transport_queues_poison	low, high, none, normal	messages/s
hyperv.vms_health	ok, critical	vms
hyperv.root_partition_device_space_pages	4K, 2M, 1G	pages
hyperv.root_partition_gpa_space_pages	4K, 2M, 1G	pages
hyperv.root_partition_gpa_space_modifications	gpa	modifications/s
hyperv.root_partition_attached_devices	attached	devices
hyperv.root_partition_deposited_pages	deposited	pages
hyperv.root_partition_skipped_interrupts	skipped	interrupts
hyperv.root_partition_device_dma_errors	illegal_dma	requests
hyperv.root_partition_device_interrupt_errors	illegal_interrupt	requests
hyperv.root_partition_device_interrupt_throttle_events	throttling	events
hyperv.root_partition_io_tlb_flush	flushes	flushes/s
hyperv.root_partition_address_space	address_spaces	address spaces
hyperv.root_partition_virtual_tlb_flush_entries	flushes	flushes/s
hyperv.root_partition_virtual_tlb_pages	used	pages

Per cpu core

TBD

Labels:

Label	Description
core	TBD

Metrics:

Metric	Dimensions	Unit
windows.cpu_core_utilization	dpc, user, privileged, interrupt	percentage
windows.cpu_core_interrupts	interrupts	interrupts/s
windows.cpu_core_dpcs	dpcs	dpcs/s
windows.cpu_core_cstate	c1, c2, c3	percentage

Per logical disk

TBD

Labels:

Label	Description
disk	TBD

Metrics:

Metric	Dimensions	Unit
windows.logical_disk_utilization	free, used	bytes
windows.logical_disk_bandwidth	read, write	bytes/s
windows.logical_disk_operations	reads, writes	operations/s
windows.logical_disk_latency	read, write	seconds

Per network device

TBD

Labels:

Label	Description
nic	TBD

Metrics:

Metric	Dimensions	Unit
windows.net_nic_bandwidth	received, sent	kilobits/s
windows.net_nic_packets	received, sent	packets/s
windows.net_nic_errors	inbound, outbound	errors/s
windows.net_nic_discarded	inbound, outbound	discards/s

Per thermalzone

TBD

Labels:

Label	Description
thermalzone	TBD

Metrics:

Metric	Dimensions	Unit
windows.thermalzone_temperature	temperature	celsius

Per service

TBD

Labels:

Label	Description
service	TBD

Metrics:

Metric	Dimensions	Unit
windows.service_state	running, stopped, start_pending, stop_pending, continue_pending, pause_pending, paused, unknown	state
windows.service_status	ok, error, unknown, degraded, pred_fail, starting, stopping, service, stressed, nonrecover, no_contact, lost_comm	status

Per website

TBD

Labels:

Label	Description
website	TBD

Metrics:

Metric	Dimensions	Unit
iis.website_traffic	received, sent	bytes/s
iis.website_requests_rate	requests	requests/s
iis.website_active_connections_count	active	connections
iis.website_users_count	anonymous, non_anonymous	users
iis.website_connection_attempts_rate	connection	attempts/s
iis.website_isapi_extension_requests_count	isapi	requests
iis.website_isapi_extension_requests_rate	isapi	requests/s
iis.website_ftp_file_transfer_rate	received, sent	files/s
iis.website_logon_attempts_rate	logon	attempts/s
iis.website_errors_rate	document_locked, document_not_found	errors/s
iis.website_uptime	document_locked, document_not_found	seconds

Per mssql instance

TBD

Labels:

Label	Description
mssql_instance	TBD

Metrics:

Metric	Dimensions	Unit
mssql.instance_accessmethods_page_splits	page	splits/s
mssql.instance_cache_hit_ratio	hit_ratio	percentage
mssql.instance_bufman_checkpoint_pages	flushed	pages/s
mssql.instance_bufman_page_life_expectancy	life_expectancy	seconds
mssql.instance_bufman_iops	read, written	iops
mssql.instance_blocked_processes	blocked	processes
mssql.instance_user_connection	user	connections
mssql.instance_locks_lock_wait	alloc_unit, application, database, extent, file, hobt, key, metadata, oib, object, page, rid, row_group, xact	locks/s
mssql.instance_locks_deadlocks	alloc_unit, application, database, extent, file, hobt, key, metadata, oib, object, page, rid, row_group, xact	locks/s
mssql.instance_memmgr_connection_memory_bytes	memory	bytes
mssql.instance_memmgr_external_benefit_of_memory	benefit	bytes
mssql.instance_memmgr_pending_memory_grants	pending	processes
mssql.instance_memmgr_server_memory	memory	bytes
mssql.instance_sql_errors	db_offline, info, kill_connection, user	errors
mssql.instance_sqlstats_auto_parameterization_attempts	failed	attempts/s
mssql.instance_sqlstats_batch_requests	batch	requests/s
mssql.instance_sqlstats_safe_auto_parameterization_attempts	safe	attempts/s
mssql.instance_sqlstats_sql_compilations	compilations	compilations/s
mssql.instance_sqlstats_sql_recompilations	recompiles	recompiles/s

Per database

TBD

Labels:

Label	Description
mssql_instance	TBD
database	TBD

Metrics:

Metric	Dimensions	Unit
mssql.database_active_transactions	active	transactions
mssql.database_backup_restore_operations	backup	operations/s
mssql.database_data_files_size	size	bytes
mssql.database_log_flushed	flushed	bytes/s
mssql.database_log_flushes	log	flushes/s
mssql.database_transactions	transactions	transactions/s
mssql.database_write_transactions	write	transactions/s

Per certificate template

TBD

Labels:

Label	Description
cert_template	TBD

Metrics:

Metric	Dimensions	Unit
adcs.cert_template_requests	requests	requests/s
adcs.cert_template_failed_requests	failed	requests/s
adcs.cert_template_issued_requests	issued	requests/s
adcs.cert_template_pending_requests	pending	requests/s
adcs.cert_template_request_processing_time	processing_time	seconds
adcs.cert_template_retrievals	retrievals	retrievals/s
adcs.cert_template_retrieval_processing_time	processing_time	seconds
adcs.cert_template_request_cryptographic_signing_time	singing_time	seconds
adcs.cert_template_request_policy_module_processing	processing_time	seconds
adcs.cert_template_challenge_responses	challenge	responses/s
adcs.cert_template_challenge_response_processing_time	processing_time	seconds
adcs.cert_template_signed_certificate_timestamp_lists	processed	lists/s
adcs.cert_template_signed_certificate_timestamp_list_processing_time	processing_time	seconds

Per process

TBD

Labels:

Label	Description
process	TBD

Metrics:

Metric	Dimensions	Unit
netframework.clrexception_thrown	exceptions	exceptions/s
netframework.clrexception_filters	filters	filters/s
netframework.clrexception_finallys	finallys	finallys/s
netframework.clrexception_throw_to_catch_depth	traversed	stack_frames/s
netframework.clrinterop_com_callable_wrappers	com_callable_wrappers	ccw/s
netframework.clrinterop_interop_marshallings	marshallings	marshallings/s
netframework.clrinterop_interop_stubs_created	created	stubs/s
netframework.clrjit_methods	jit-compiled	methods/s
netframework.clrjit_time	time	percentage
netframework.clrjit_standard_failures	failures	failures/s
netframework.clrjit_il_bytes	compiled_msil	bytes/s
netframework.clrloading_loader_heap_size	committed	bytes
netframework.clrloading_appdomains_loaded	loaded	domain/s
netframework.clrloading_appdomains_unloaded	unloaded	domain/s
netframework.clrloading_assemblies_loaded	loaded	assemblies/s
netframework.clrloading_classes_loaded	loaded	classes/s
netframework.clrloading_class_load_failures	class_load	failures/s
netframework.clrlocksandthreads_queue_length	threads	threads/s
netframework.clrlocksandthreads_current_logical_threads	logical	threads
netframework.clrlocksandthreads_current_physical_threads	physical	threads
netframework.clrlocksandthreads_recognized_threads	threads	threads/s
netframework.clrlocksandthreads_contentions	contentions	contentions/s
netframework.clrmemory_allocated_bytes	allocated	bytes/s
netframework.clrmemory_finalization_survivors	survived	objects
netframework.clrmemory_heap_size	heap	bytes
netframework.clrmemory_promoted	promoted	bytes
netframework.clrmemory_number_gc_handles	used	handles
netframework.clrmemory_collections	gc	gc/s
netframework.clrmemory_induced_gc	gc	gc/s
netframework.clrmemory_number_pinned_objects	pinned	objects
netframework.clrmemory_number_sink_blocks_in_use	used	blocks
netframework.clrmemory_committed	committed	bytes
netframework.clrmemory_reserved	reserved	bytes
netframework.clrmemory_gc_time	time	percentage
netframework.clrremoting_channels	registered	channels/s
netframework.clrremoting_context_bound_classes_loaded	loaded	classes
netframework.clrremoting_context_bound_objects	allocated	objects/s
netframework.clrremoting_context_proxies	objects	objects/s
netframework.clrremoting_contexts	contexts	contexts
netframework.clrremoting_remote_calls	rpc	calls/s
netframework.clrsecurity_link_time_checks	linktime	checks/s
netframework.clrsecurity_checks_time	time	percentage
netframework.clrsecurity_stack_walk_depth	stack	depth
netframework.clrsecurity_runtime_checks	runtime	checks/s

Per exchange workload

TBD

Labels:

Label	Description
workload	TBD

Metrics:

Metric	Dimensions	Unit
exchange.workload_active_tasks	active	tasks
exchange.workload_completed_tasks	completed	tasks/s
exchange.workload_queued_tasks	queued	tasks/s
exchange.workload_yielded_tasks	yielded	tasks/s
exchange.workload_activity_status	active, paused	status

Per ldap process

TBD

Labels:

Label	Description
workload	TBD

Metrics:

Metric	Dimensions	Unit
exchange.ldap_long_running_ops_per_sec	long-running	operations/s
exchange.ldap_read_time	read	seconds
exchange.ldap_search_time	search	seconds
exchange.ldap_write_time	write	seconds
exchange.ldap_timeout_errors	timeout	errors/s

Per http proxy

TBD

Labels:

Label	Description
workload	TBD

Metrics:

Metric	Dimensions	Unit
exchange.http_proxy_avg_auth_latency	latency	seconds
exchange.http_proxy_avg_cas_processing_latency_sec	latency	seconds
exchange.http_proxy_mailbox_proxy_failure_rate	failures	percentage
exchange.http_proxy_mailbox_server_locator_avg_latency_sec	latency	seconds
exchange.http_proxy_outstanding_proxy_requests	outstanding	requests
exchange.http_proxy_requests	processed	requests/s

Per vm

TBD

Labels:

Label	Description
vm_name	TBD

Metrics:

Metric	Dimensions	Unit
hyperv.vm_cpu_usage	gues, hypervisor, remote	percentage
hyperv.vm_memory_physical	assigned_memory	MiB
hyperv.vm_memory_physical_guest_visible	visible_memory	MiB
hyperv.vm_memory_pressure_current	pressure	percentage
hyperv.vm_vid_physical_pages_allocated	allocated	pages
hyperv.vm_vid_remote_physical_pages	remote_physical	pages

Per vm device

TBD

Labels:

Label	Description
vm_device	TBD

Metrics:

Metric	Dimensions	Unit
hyperv.vm_device_bytes	read, written	bytes/s
hyperv.vm_device_operations	read, write	operations/s
hyperv.vm_device_errors	errors	errors/s

Per vm interface

TBD

Labels:

Label	Description
vm_interface	TBD

Metrics:

Metric	Dimensions	Unit
hyperv.vm_interface_bytes	received, sent	bytes/s
hyperv.vm_interface_packets	received, sent	packets/s
hyperv.vm_interface_packets_dropped	incoming, outgoing	drops/s

Per vswitch

TBD

Labels:

Label	Description
vswitch	TBD

Metrics:

Metric	Dimensions	Unit
hyperv.vswitch_bytes	received, sent	bytes/s
hyperv.vswitch_packets	received, sent	packets/s
hyperv.vswitch_directed_packets	received, sent	packets/s
hyperv.vswitch_broadcast_packets	received, sent	packets/s
hyperv.vswitch_multicast_packets	received, sent	packets/s
hyperv.vswitch_dropped_packets	incoming, outgoing	drops/s
hyperv.vswitch_extensions_dropped_packets	incoming, outgoing	drops/s
hyperv.vswitch_packets_flooded	flooded	packets/s
hyperv.vswitch_learned_mac_addresses	learned	mac addresses/s
hyperv.vswitch_purged_mac_addresses	purged	mac addresses/s

Alerts

The following alerts are available:

Alert name	On metric	Description
windows_10min_cpu_usage	windows.cpu_utilization_total	average CPU utilization over the last 10 minutes
windows_ram_in_use	windows.memory_utilization	memory utilization
windows_inbound_packets_discarded	windows.net_nic_discarded	number of inbound discarded packets for the network interface in the last 10 minutes
windows_outbound_packets_discarded	windows.net_nic_discarded	number of outbound discarded packets for the network interface in the last 10 minutes
windows_inbound_packets_errors	windows.net_nic_errors	number of inbound errors for the network interface in the last 10 minutes
windows_outbound_packets_errors	windows.net_nic_errors	number of outbound errors for the network interface in the last 10 minutes
windows_disk_in_use	windows.logical_disk_space_usage	disk space utilization

Setup

Prerequisites

Install Windows exporter

To install the Windows exporter, follow the official installation guide.

Configuration

File

The configuration file name for this integration is go.d/windows.conf.

You can edit the configuration file using the edit-config script from the Netdata config directory.

cd /etc/netdata 2>/dev/null || cd /opt/netdata/etc/netdata
sudo ./edit-config go.d/windows.conf

Options

The following options can be defined globally: update_every, autodetection_retry.

Config options

Name	Description	Default	Required
update_every	Data collection frequency.	1	no
autodetection_retry	Recheck interval in seconds. Zero means no recheck will be scheduled.	0	no
url	Server URL.		yes
timeout	HTTP request timeout.	1	no
username	Username for basic HTTP authentication.		no
password	Password for basic HTTP authentication.		no
proxy_url	Proxy URL.		no
proxy_username	Username for proxy basic HTTP authentication.		no
proxy_password	Password for proxy basic HTTP authentication.		no
method	HTTP request method.	GET	no
body	HTTP request body.		no
headers	HTTP request headers.		no
not_follow_redirects	Redirect handling policy. Controls whether the client follows redirects.	no	no
tls_skip_verify	Server certificate chain and hostname validation policy. Controls whether the client performs this check.	no	no
tls_ca	Certification authority that the client uses when verifying the server's certificates.		no
tls_cert	Client TLS certificate.		no
tls_key	Client TLS key.		no

Examples

Basic

A basic example configuration.

jobs:
  - name: win_server
    url: http://192.0.2.1:9182/metrics

HTTP authentication

Basic HTTP authentication.

Config

jobs:
  - name: win_server
    url: http://192.0.2.1:9182/metrics
    username: username
    password: password

HTTPS with self-signed certificate

Do not validate server certificate chain and hostname.

Config

jobs:
  - name: win_server
    url: https://192.0.2.1:9182/metrics
    tls_skip_verify: yes

Virtual Node

The Virtual Node functionality allows you to define nodes in configuration files and treat them as ordinary nodes in all interfaces, panels, tabs, filters, etc. You can create a virtual node for all your Windows machines and control them as separate entities.

To make your Windows server a virtual node, you need to define virtual nodes in /etc/netdata/vnodes/vnodes.conf:

Note: To create a valid guid, you can use the uuidgen command on Linux, or the [guid]::NewGuid() command in PowerShell on Windows.

# /etc/netdata/vnodes/vnodes.conf
- hostname: win_server
  guid: <value>

Config

jobs:
  - name: win_server
    vnode: win_server
    url: http://192.0.2.1:9182/metrics

Multi-instance

Note: When you define multiple jobs, their names must be unique.

Collecting metrics from multiple remote instances.

Config

jobs:
  - name: win_server1
    url: http://192.0.2.1:9182/metrics

  - name: win_server2
    url: http://192.0.2.2:9182/metrics

Troubleshooting

Debug Mode

Important: Debug mode is not supported for data collection jobs created via the UI using the Dyncfg feature.

To troubleshoot issues with the windows collector, run the go.d.plugin with the debug option enabled. The output should give you clues as to why the collector isn't working.

• Navigate to the plugins.d directory, usually at /usr/libexec/netdata/plugins.d/. If that's not the case on your system, open netdata.conf and look for the plugins setting under [directories].

  cd /usr/libexec/netdata/plugins.d/

• Switch to the netdata user.

  sudo -u netdata -s

• Run the go.d.plugin to debug the collector:

  ./go.d.plugin -d -m windows

Getting Logs

If you're encountering problems with the windows collector, follow these steps to retrieve logs and identify potential issues:

• Run the command specific to your system (systemd, non-systemd, or Docker container).
• Examine the output for any warnings or error messages that might indicate issues. These messages should provide clues about the root cause of the problem.

System with systemd

Use the following command to view logs generated since the last Netdata service restart:

journalctl _SYSTEMD_INVOCATION_ID="$(systemctl show --value --property=InvocationID netdata)" --namespace=netdata --grep windows

System without systemd

Locate the collector log file, typically at /var/log/netdata/collector.log, and use grep to filter for collector's name:

grep windows /var/log/netdata/collector.log

Note: This method shows logs from all restarts. Focus on the latest entries for troubleshooting current issues.

Docker Container

If your Netdata runs in a Docker container named "netdata" (replace if different), use this command:

docker logs netdata 2>&1 | grep windows