Skip to navigation
Use AIStore

ais cluster command

View as Markdown

The ais cluster command is the main tool for monitoring and managing an AIS (AIStore) cluster. It provides functionalities to

  • add or remove nodes
  • change the primary gateway
  • join (or merge) two AIS clusters, and
  • perform a variety of administrative operations.

The command has the following subcommands:

$ ais cluster <TAB-TAB>
show                   rebalance              decommission           drop-lcache
dashboard              set-primary            add-remove-nodes       reload-backend-creds
remote-attach          download-logs          placement
remote-detach          shutdown               reset-stats

Important: with the single exception of add-remove-nodes, all the other the commands listed above operate on the level of the entire cluster. Node level operations (e.g., shutting down a given selected node, etc.) can be found under add-remove-nodes.

Alternatively, use --help to show subcommands with brief descriptions:

$ ais cluster  --help
NAME:
   ais cluster - Monitor and manage AIS cluster: add/remove nodes, change primary gateway, etc.
USAGE:
   ais cluster command [arguments...]  [command options]
COMMANDS:
   show                  Main dashboard: show cluster at-a-glance (nodes, software versions, utilization, capacity, memory and more)
   remote-attach         Attach remote ais cluster
   remote-detach         Detach remote ais cluster
   rebalance             Administratively start and stop global rebalance; show global rebalance
   set-primary           Select a new primary proxy/gateway
   download-logs         Download all log archives from all clustered nodes (one TAR.GZ per node), e.g.:
                          - 'download-logs /tmp/www' - save log archives to /tmp/www directory
                          - 'download-logs --severity w' - errors and warnings to /tmp directory
                            (see related: 'ais log show', 'ais log get')
   shutdown              Shut down entire cluster
   decommission          Decommission entire cluster
   add-remove-nodes      Manage cluster membership (add/remove nodes, temporarily or permanently)
   placement             Show and set target placement weights
   reset-stats           Reset cluster or node stats (all cumulative metrics or only errors)
   drop-lcache           Drop (discard) in-memory object metadata cache
   reload-backend-creds  Reload (updated) backend credentials
OPTIONS:
   --help, -h  Show help

As always, each subcommand will have its own help and usage examples, the latter possibly spread across multiple documents.

Note: for any keyword or text of any kind, you can easily look up examples and descriptions via a simple find or git grep, for instance:

$ find . -type f -name "*.md" | xargs grep "ais.*mountpath"

Note that there is a single CLI command to grow a cluster, and multiple commands to scale it down.

Scaling down can be done gracefully or forcefully, and also temporarily or permanently.

For background, usage examples, and details, please see Node lifecycle: maintenance, shutdown, decommission.

Adding/removing nodes

The corresponding functionality can be found under the subcommand called add-remove-nodes:

$ ais cluster add-remove-nodes --help
NAME:
   ais cluster add-remove-nodes - manage cluster membership (add/remove nodes, temporarily or permanently)
USAGE:
   ais cluster add-remove-nodes command [arguments...] [command options]
COMMANDS:
   join               add a node to the cluster
   start-maintenance  put node in maintenance mode, temporarily suspend its operation
   stop-maintenance   activate node by taking it back from "maintenance"
   decommission       safely and permanently remove node from the cluster
   shutdown           shutdown a node, gracefully or immediately;
                      note: upon shutdown the node won't be decommissioned - it'll remain in the cluster map
                      and can be manually restarted to rejoin the cluster at any later time;
                      see also: 'ais advanced remove-from-smap'

Table of Contents

Cluster Dashboard

ais show dashboard (alias: ais cluster dashboard) provides an at-a-glance view of cluster health, performance, and configuration. The dashboard consolidates the most important operational metrics into a single command, making it ideal for quick status checks and continuous monitoring.

Command Overview

$ ais show dashboard --help
NAME:
   ais show dashboard - Show cluster at-a-glance dashboard: node counts, capacity, performance, health, software version, and more
USAGE:
   ais show dashboard [NODE_ID] [command options]
OPTIONS:
   --refresh value   interval for continuous monitoring;
                     valid time units: ns, us (or µs), ms, s (default), m, h
   --count value     used together with '--refresh' to limit the number of generated reports (default: 0)
   --verbose, -v     verbose output
   --json, -j        json input/output
   --no-headers, -H  display tables without headers
   --help, -h        show help

Output Sections

The dashboard displays two main sections:

Performance and Health:

MetricDescription
StateOverall cluster operational status (Operational, Critical, Maintenance, etc.)
ThroughputCurrent read/write throughput rates (shown only when active)
I/O ErrorsTotal disk I/O errors across all nodes
Load Avg1-minute load average (avg, min, max across all nodes)
Disk UsageAverage, minimum, and maximum disk usage percentages
NetworkNetwork health status
StorageTotal mountpaths and their health status
FilesystemsTypes and counts of filesystems in use
Running JobsCurrently active job types (if any)

Cluster:

MetricDescription
EndpointCluster endpoint URL
ProxiesNumber of proxy nodes and electability status
TargetsNumber of target nodes and total disks
CapacityUsed and available storage with percentages
Cluster MapVersion, UUID, and primary node information
SoftwareVersion and build information
BackendConfigured backend provider(s)
DeploymentDeployment type (K8s, standalone, etc.)
StatusOnline node count
RebalanceCurrent rebalance status
AuthenticationWhether AuthN is enabled
Version/BuildSoftware version and build timestamp

Examples

Basic dashboard view:

$ ais show dashboard
Performance and Health:
   State:               Operational
   Throughput:          Read 9.5GiB/s, Write 0B/s (1s avg)
   I/O Errors:          0
   Load Avg:            avg 2.1, min 1.6, max 2.7 (1m)
   Disk Usage:          avg 19.3%, min 18.8%, max 20.1%
   Network:             healthy
   Storage:             192 mountpaths (all healthy)
   Filesystems:         xfs(192)
   Running Jobs:        None
Cluster:
   Endpoint:            https://asr.aistore.nvidia.com:51080
   Proxies:             16 (all electable)
   Targets:             16 (total disks: 192)
   Capacity:            used 591.40TiB (49%), available 595.89TiB
   Cluster Map:         version 103, UUID cwV4IkK3k, primary p[Euc2iyom3zhi6]
   Software:            3.31.a210cc0 (build: 2025-07-25T22:44:30+0000)
   Backend:             AWS
   Deployment:          K8s
   Status:              32 online
   Rebalance:           n/a
   Authentication:      disabled
   Version:             3.31.a210cc0
   Build:               2025-07-25T22:44:30+0000

Continuous (Throughput) monitoring:

# Compute cluster throughput numbers over 30s intervals; refresh every 30 seconds
$ ais show dashboard --refresh 30
# Same as above but run 10 times (6m total)
$ ais show dashboard --refresh 30 --count 10

JSON output:

$ ais show dashboard --json

Verbose mode (shows detailed issue breakdown when problems detected):

$ ais show dashboard --verbose
Performance and Health:
   State:               Multiple issues (6 node(s) affected: 2 maintenance, 4 rebalancing)
   ...
CLUSTER HEALTH DETAILS:
Maintenance (2/6):   t[FFIt8090], t[zHut8091]
Rebalancing (4/6):   t[ZHHt8087], t[atEt8086], t[UTat8088], t[xgAt8089]

Cluster and Node status

The command has a rather long(ish) short description and multiple subcommands:

$ ais show cluster --help
NAME:
   ais show cluster - main dashboard: cluster at-a-glance (nodes, software versions, utilization, capacity, memory and more)
USAGE:
   ais show cluster command [NODE_ID] | [target [NODE_ID]] | [proxy [NODE_ID]] | [command options]
                       [smap [NODE_ID]] | [bmd [NODE_ID]] | [config [NODE_ID]] | [stats [NODE_ID]]
COMMANDS:
   smap    show cluster map (Smap)
   bmd     show bucket metadata (BMD)
   config  show cluster and node configuration
   stats   (alias for "ais show performance") show performance counters, throughput, latency and more (press <TAB-TAB> to select specific view)
OPTIONS:
   --refresh value   interval for continuous monitoring;
                     valid time units: ns, us (or µs), ms, s (default), m, h
   --count value     used together with '--refresh' to limit the number of generated reports (default: 0)
   --json, -j        json input/output
   --no-headers, -H  display tables without headers
   --help, -h        show help

To quickly exemplify, let’s assume the cluster has a (target) node called t[xyz]. Then:

Main CLI dashboard: all storage nodes and gateways, deployed version, capacity, memory, and runtime stats:

$ ais show cluster

same as above, with only targets selected

$ ais show cluster target

show specific target

$ ais show cluster target t[xyz]

ask specific target to show its cluster map

$ ais show cluster smap t[xyz]

and so on and so forth.

Notes

The last example (above) may potentially make sense when troubleshooting. Otherwise, by design and implementation, cluster map (Smap), bucket metadata (BMD), and all other cluster-level metadata exists in identical protected and versioned replicas on all nodes at any given point in time.

Still, to display cluster map in its (JSON) fullness, run:

$ ais show cluster smap --json

--json option is almost universally supported in CLI

Similar to all other show commands, ais cluster show is an alias for ais cluster show. Both can be used interchangeably.

Options

$ ais show cluster smap --help
NAME:
   ais show cluster smap - Show cluster map (Smap)
USAGE:
   ais show cluster smap [NODE_ID] [command options]
OPTIONS:
   --count value     Used together with '--refresh' to limit the number of generated reports, e.g.:
                      '--refresh 10 --count 5' - run 5 times with 10s interval (default: 0)
   --json, -j        JSON input/output
   --no-headers, -H  Display tables without headers
   --refresh value   Time interval for continuous monitoring; can be also used to update progress bar (at a given interval);
                     valid time units: ns, us (or µs), ms, s (default), m, h
   --help, -h        Show help

Examples

$ ais show cluster
PROXY            MEM USED %      MEM AVAIL       UPTIME
pufGp8080[P]     0.28%           15.43GiB        17m
ETURp8083        0.26%           15.43GiB        17m
sgahp8082        0.26%           15.43GiB        17m
WEQRp8084        0.27%           15.43GiB        17m
Watdp8081        0.26%           15.43GiB        17m
TARGET           MEM USED %      MEM AVAIL       CAP USED %      CAP AVAIL       CPU USED %      REBALANCE       UPTIME
iPbHt8088        0.28%           15.43GiB        14.00%          1.178TiB        0.13%           -               17m
Zgmlt8085        0.28%           15.43GiB        14.00%          1.178TiB        0.13%           -               17m
oQZCt8089        0.28%           15.43GiB        14.00%          1.178TiB        0.14%           -               17m
dIzMt8086        0.28%           15.43GiB        14.00%          1.178TiB        0.13%           -               17m
YodGt8087        0.28%           15.43GiB        14.00%          1.178TiB        0.14%           -               17m
Summary:
 Proxies:       5 (0 - unelectable)
 Targets:       5
 Primary Proxy: pufGp8080
 Smap Version:  14
 Deployment:    dev

Show cluster map

ais show cluster smap [NODE_ID]

Show a copy of the cluster map (Smap) stored on NODE_ID.

If NODE_ID is not given, show cluster map from (primary or secondary) proxy “pointed to” by your local CLI configuration (ais config cli) or AIS_ENDPOINT environment.

Note that cluster map (Smap), bucket metadata (BMD), and all other cluster-level metadata exists in identical protected and versioned replicas on all nodes at any given point in time.

Useful variations include ais show cluster smap --json (to see the unabridged version), and also:

$ ais show cluster smap --refresh 5

The latter will periodically (until Ctrl-C) show cluster map in 5-second intervals - might be useful in presence of any kind of membership changes (e.g., cluster startup).

Options

$ ais show cluster smap --help
NAME:
   ais show cluster smap - Show cluster map (Smap)
USAGE:
   ais show cluster smap [NODE_ID] [command options]
OPTIONS:
   --count value     Used together with '--refresh' to limit the number of generated reports, e.g.:
                      '--refresh 10 --count 5' - run 5 times with 10s interval (default: 0)
   --json, -j        JSON input/output
   --no-headers, -H  Display tables without headers
   --refresh value   Time interval for continuous monitoring; can be also used to update progress bar (at a given interval);
                     valid time units: ns, us (or µs), ms, s (default), m, h
   --help, -h        Show help

Examples

Show smap from a given node

Ask a specific node for its cluster map (Smap) replica:

$ ais show cluster smap <TAB-TAB>
... p[ETURp8083] ...
$ ais show cluster smap p[ETURp8083]
NODE             TYPE    PUBLIC URL
ETURp8083        proxy   http://127.0.0.1:8083
WEQRp8084        proxy   http://127.0.0.1:8084
Watdp8081        proxy   http://127.0.0.1:8081
pufGp8080[P]     proxy   http://127.0.0.1:8080
sgahp8082        proxy   http://127.0.0.1:8082
NODE             TYPE    PUBLIC URL
YodGt8087        target  http://127.0.0.1:8087
Zgmlt8085        target  http://127.0.0.1:8085
dIzMt8086        target  http://127.0.0.1:8086
iPbHt8088        target  http://127.0.0.1:8088
oQZCt8089        target  http://127.0.0.1:8089
Non-Electable:
Primary Proxy: pufGp8080
Proxies: 5       Targets: 5      Smap Version: 14

Show cluster stats

ais show cluster stats is a alias for ais show performance.

The latter is the primary implementation, and the preferred way to investigate cluster performance, while ais show cluster stats is retained in part for convenience and in part for backward compatibility.

$ ais show cluster stats <TAB-TAB>
counters     throughput   latency      capacity     intra-data   disk
$ ais show cluster stats --help
NAME:
   ais show cluster stats - (alias for "show performance") Show performance counters, throughput, latency, disks, used/available capacities (press <TAB-TAB> to select specific view)
USAGE:
   ais show cluster stats [TARGET_ID]  [command options]
COMMANDS:
   counters    Show (GET, PUT, DELETE, RENAME, EVICT, APPEND) object counts, as well as:
               - numbers of list-objects requests;
               - (GET, PUT, etc.) cumulative and average sizes;
               - associated error counters, if any, and more.
   throughput  Show GET and PUT throughput, associated (cumulative, average) sizes and counters.
               Examples:
               - 'ais performance throughput --refresh 10'            - update every 10s;
               - 'ais performance throughput --refresh 10 --count 5'  - 5 iterations, 10s apart.
   latency     Show GET, PUT, and APPEND latencies and average sizes.
               Examples:
               - 'ais performance latency --refresh 10'            - update every 10s;
               - 'ais performance latency --refresh 10 --count 5'  - 5 iterations, 10s apart.
   capacity    Show target mountpaths, disks, and used/available capacity
   intra-data  Show intra-cluster streaming traffic: RX/TX object counts, sizes, throughput, and average size.
               Examples:
               - 'ais performance intra-data --refresh 10'            - update every 10s;
               - 'ais performance intra-data --refresh 10 --count 5'  - 5 iterations, 10s apart.
   disk        Show disk utilization and read/write statistics
OPTIONS:
   --average-size       Show average GET, PUT, etc. request size
   --count value        Used together with '--refresh' to limit the number of generated reports, e.g.:
                         '--refresh 10 --count 5' - run 5 times with 10s interval (default: 0)
   --no-headers, -H     Display tables without headers
   --non-verbose, --nv  Non-verbose (quiet) output, minimized reporting, fewer warnings
   --refresh value      Time interval for continuous monitoring; can be also used to update progress bar (at a given interval);
                        valid time units: ns, us (or µs), ms, s (default), m, h
   --regex value        Regular expression to select table columns (case-insensitive), e.g.:
                         --regex "put|err" - show PUT (count), PUT (total size), and all supported error counters;
                         --regex "Put|ERR" - same as above;
                         --regex "[a-z]" - show all supported metrics, including those that have zero values across all nodes;
                         --regex "aws-get|version-change" - show AWS backend reads and out-of-band object version changes;
                         --regex "gcp-get|version-change" - same as above for Google Cloud ('gs://')
   --units value        Show statistics and/or parse command-line specified sizes using one of the following units of measurement:
                        iec - IEC format, e.g.: KiB, MiB, GiB (default)
                        si  - SI (metric) format, e.g.: KB, MB, GB
                        raw - do not convert to (or from) human-readable format
   --verbose, -v        Verbose output
   --help, -h           Show help

See also:

Show disk stats

ais show storage disk [TARGET_ID] - show disk utilization and read/write statistics

$ ais show storage disk --help
NAME:
   ais show storage disk - Show disk utilization and read/write statistics
USAGE:
   ais show storage disk [TARGET_ID] [command options]
OPTIONS:
   count         Used together with '--refresh' to limit the number of generated reports, e.g.:
                  '--refresh 10 --count 5' - run 5 times with 10s interval
   no-headers,H  Display tables without headers
   refresh       Time interval for continuous monitoring; can be also used to update progress bar (at a given interval);
                 valid time units: ns, us (or µs), ms, s (default), m, h
   regex         Regular expression to select table columns (case-insensitive), e.g.:
                  --regex "put|err" - show PUT (count), PUT (total size), and all supported error counters;
                  --regex "Put|ERR" - same as above;
                  --regex "[a-z]" - show all supported metrics, including those that have zero values across all nodes;
                  --regex "aws-get|version-change" - show AWS backend reads and out-of-band object version changes;
                  --regex "gcp-get|version-change" - same as above for Google Cloud ('gs://')
   summary       Tally up target disks to show per-target read/write summary stats and average utilizations
   units         Show statistics and/or parse command-line specified sizes using one of the following units of measurement:
                 iec - IEC format, e.g.: KiB, MiB, GiB (default)
                 si  - SI (metric) format, e.g.: KB, MB, GB
                 raw - do not convert to (or from) human-readable format
   help, h       Show help

When TARGET_ID is not given, disk stats for all targets will be shown and aggregated.

Examples

Display disk reports stats N times every M seconds

Display 5 reports of all targets’ disk statistics, with 10s intervals between each report.

$ ais show storage disk --count 2 --refresh 10s
Target		Disk	Read		Write		%Util
163171t8088	sda	6.00KiB/s	171.00KiB/s	49
948212t8089	sda	6.00KiB/s	171.00KiB/s	49
41981t8085	sda	6.00KiB/s	171.00KiB/s	49
490062t8086	sda	6.00KiB/s	171.00KiB/s	49
164472t8087	sda	6.00KiB/s	171.00KiB/s	49
Target		Disk	Read		Write		%Util
163171t8088	sda	1.00KiB/s	4.26MiB/s	96
41981t8085	sda	1.00KiB/s	4.26MiB/s	96
948212t8089	sda	1.00KiB/s	4.26MiB/s	96
490062t8086	sda	1.00KiB/s	4.29MiB/s	96
164472t8087	sda	1.00KiB/s	4.26MiB/s	96

Managing cluster membership

The ais cluster add-remove-nodes command supports adding, removing, and maintaining nodes within the cluster. It allows administrators to dynamically adjust the cluster’s composition, handle maintenance operations, and ensure availability and correctness during transitions when nodes are added or removed.

$ ais cluster add-remove-nodes --help
NAME:
   ais cluster add-remove-nodes - Manage cluster membership (add/remove nodes, temporarily or permanently)
USAGE:
   ais cluster add-remove-nodes command [arguments...]  [command options]
COMMANDS:
   join               Add a node to the cluster
   start-maintenance  Put node in maintenance mode, temporarily suspend its operation
   stop-maintenance   Take node out of maintenance mode - activate
   decommission       Safely and permanently remove node from the cluster
   shutdown           Shutdown a node, gracefully or immediately;
                      note: upon shutdown the node won't be decommissioned - it'll remain in the cluster map
                      and can be manually restarted to rejoin the cluster at any later time;
                      see also: 'ais advanced remove-from-smap'
OPTIONS:
   --help, -h  Show help

Join a node

$ ais cluster add-remove-nodes join --help
NAME:
   ais cluster add-remove-nodes join - add a node to the cluster
USAGE:
   ais cluster add-remove-nodes join IP:PORT [command options]
OPTIONS:
   --role value     role of this AIS daemon: proxy or target
   --non-electable  this proxy must not be elected as primary (advanced use)
   --help, -h       show help

AIStore has two kinds of node: proxie (gateways) and targets (storage nodes). That’s why --role is a mandatory option that must have one of the two values:

  • --role=proxy or
  • --role=target

Note: aisnode will try to join cluster using its persistent ID. If you need to specify an ID, you can do so via aisnode executable command line.

Example: join a proxy node

$ ais cluster add-remove-nodes join --role=proxy 192.168.0.185:8086
Proxy with ID "23kfa10f" successfully joined the cluster.

Any proxy can be potentially elected as primary; to mark certain proxies as non-electable, run (e.g.):

$ ais cluster add-remove-nodes join 192.168.0.185:8086 --role=proxy --non-electable

Remove a node

Temporarily remove an existing node from the cluster

ais cluster add-remove-nodes start-maintenance NODE_ID ais cluster add-remove-nodes stop-maintenance NODE_ID

Starting maintenance puts the node in maintenance mode, and the cluster gradually transitions to operating without the specified node (which is labeled maintenance in the cluster map). Stopping maintenance will revert this.

ais cluster add-remove-nodes shutdown NODE_ID

Shutting down a node will put the node in maintenance mode first, and then shut down the aisnode process on the node.

Permanently remove an existing node from the cluster

ais cluster add-remove-nodes decommission NODE_ID

Decommissioning a node will safely remove a node from the cluster by triggering a cluster-wide rebalance first. This can be avoided by specifying --no-rebalance.

Options

$ ais cluster add-remove-nodes decommission --help
NAME:
   ais cluster add-remove-nodes decommission - Safely and permanently remove node from the cluster
USAGE:
   ais cluster add-remove-nodes decommission NODE_ID [command options]
OPTIONS:
   --keep-initial-config  Keep the original plain-text configuration the node was deployed with
                          (the option can be used to restart aisnode from scratch)
   --no-rebalance         Do _not_ run global rebalance after putting node in maintenance (caution: advanced usage only)
   --no-shutdown          Do not shutdown node upon decommissioning it from the cluster
   --rm-user-data         Remove all user data when decommissioning node from the cluster
   --yes, -y              Assume 'yes' to all questions
   --help, -h             Show help

Examples

Decommission node

Permananently remove proxy p[omWp8083] from the cluster:

$ ais cluster add-remove-nodes decommission <TAB-TAB>
p[cFOp8082]   p[Hqhp8085]   p[omWp8083]   t[bFat8087]   t[Icjt8089]   t[ofPt8091]
p[dpKp8084]   p[NGVp8081]   p[Uerp8080]   t[erbt8086]   t[IDDt8090]   t[TKSt8088]
$ ais cluster add-remove-nodes decommission p[omWp8083]
Node "omWp8083" has been successfully removed from the cluster.

To terminate aisnode on a given machine, use the shutdown command, e.g.:

$ ais cluster add-remove-nodes shutdown t[23kfa10f]

Similar to the maintenance option, shutdown triggers global rebalanceng then shuts down the corresponding aisnode process (target t[23kfa10f] in the example above).

Temporarily put node in maintenance

$ ais show cluster
PROXY            MEM USED %      MEM AVAIL       UPTIME
202446p8082      0.09%           31.28GiB        70s
279128p8080[P]   0.11%           31.28GiB        80s
TARGET           MEM USED %      MEM AVAIL       CAP USED %      CAP AVAIL       CPU USED %      REBALANCE       UPTIME
147665t8084      0.10%           31.28GiB        16%             2.458TiB        0.12%           -               70s
165274t8087      0.10%           31.28GiB        16%             2.458TiB        0.12%           -               70s
$ ais cluster add-remove-nodes start-maintenance 147665t8084
$ ais show cluster
PROXY            MEM USED %      MEM AVAIL       UPTIME
202446p8082      0.09%           31.28GiB        70s
279128p8080[P]   0.11%           31.28GiB        80s
TARGET           MEM USED %      MEM AVAIL       CAP USED %      CAP AVAIL       CPU USED %      REBALANCE       UPTIME  STATUS
147665t8084      0.10%           31.28GiB        16%             2.458TiB        0.12%           -               71s     maintenance
165274t8087      0.10%           31.28GiB        16%             2.458TiB        0.12%           -               71s     online

Take a node out of maintenance

$ ais cluster add-remove-nodes stop-maintenance t[147665t8084]
$ ais show cluster
PROXY            MEM USED %      MEM AVAIL       UPTIME
202446p8082      0.09%           31.28GiB        80s
279128p8080[P]   0.11%           31.28GiB        90s
TARGET           MEM USED %      MEM AVAIL       CAP USED %      CAP AVAIL       CPU USED %      REBALANCE       UPTIME
147665t8084      0.10%           31.28GiB        16%             2.458TiB        0.12%           -               80s
165274t8087      0.10%           31.28GiB        16%             2.458TiB        0.12%           -               80s

Remote AIS cluster

Given an arbitrary pair of AIS clusters A and B, cluster B can be attached to cluster A, thus providing (to A) a fully-accessible (list-able, readable, writeable) backend.

For background, terminology, and definitions, and for many more usage examples, please see:

Attach remote cluster

ais cluster remote-attach UUID=URL [UUID=URL...]

or

ais cluster remote-attach ALIAS=URL [ALIAS=URL...]

Attach a remote AIS cluster to a local one via the remote cluster public URL. Alias (a user-defined name) can be used instead of cluster UUID for convenience. For more details and background on remote clustering, please refer to this document.

Examples

Attach two remote clusters, the first - by its UUID, the second one - via user-friendly alias (two).

$ ais cluster remote-attach a345e890=http://one.remote:51080 two=http://two.remote:51080`

Detach remote cluster

ais cluster remote-detach UUID|ALIAS

Detach a remote cluster using its alias or UUID.

Examples

Example below assumes that the remote has user-given alias two:

$ ais cluster remote-detach two

Show remote clusters

ais show remote-cluster

Show details about attached remote clusters.

Examples

The following two commands attach and then show the remote cluster at the address my.remote.ais:51080:

$ ais cluster remote-attach alias111=http://my.remote.ais:51080
Remote cluster (alias111=http://my.remote.ais:51080) successfully attached
$ ais show remote-cluster
UUID      URL                     Alias     Primary         Smap  Targets  Online
eKyvPyHr  my.remote.ais:51080     alias111  p[80381p11080]  v27   10       yes

Notice that:

  • user can assign an arbitrary name (aka alias) to a given remote cluster
  • the remote cluster does not have to be online at attachment time; offline or currently unreachable clusters are shown as follows:
$ ais show remote-cluster
UUID        URL                       Alias     Primary         Smap  Targets  Online
eKyvPyHr    my.remote.ais:51080       alias111  p[primary1]     v27   10       no
<alias222>  <other.remote.ais:51080>            n/a             n/a   n/a      no

Notice the difference between the first and the second lines in the printout above: while both clusters appear to be currently offline (see the rightmost column), the first one was accessible at some earlier time and therefore we show that it has (in this example) 10 storage nodes and other details.

To detach any of the previously configured associations, simply run:

$ ais cluster remote-detach alias111
$ ais show remote-cluster
UUID        URL                       Alias     Primary         Smap  Targets  Online
<alias222>  <other.remote.ais:51080>            n/a             n/a   n/a      no

Placement weights

By default, objects are distributed uniformly across targets. Target placement weights (v5.2) represent relative capacities (1, 3, 6) or sizes in GB (100, 300, 600).

With weights set, each target owns a weight/sum(weights) share of objects - except in buckets with placement.weighting=uniform. Changing weights non-proportionally triggers global rebalance. To see measured per-target object counts, run ais storage summary BUCKET --per-target. See Placement weights.

$ ais cluster placement --help
NAME:
   ais cluster placement - Show and set target placement weights
USAGE:
   ais cluster placement command [arguments...]  [command options]
COMMANDS:
   show           Show target placement weights and normalized shares
   set-weights    Set target placement weights (starts global rebalance unless placement does not change):
                  - weights are positive integers, e.g. relative capacities (1, 3, 6) or sizes in GB (100, 300, 600);
                  - rest=WEIGHT assigns that weight to all unlisted targets; explicit assignments take precedence;
                  - unweighted cluster: specify a weight for every target or use rest=WEIGHT;
                  - weighted cluster: unlisted targets keep their current weights unless rest=WEIGHT is given;
                  - max/min ratio: warning at 10x, rejected at 100x;
                  - requires all nodes to run the same software version;
                  - e.g.: 'ais cluster placement set-weights t[abc]=123 rest=456'
   clear-weights  Clear all target placement weights (starts global rebalance unless placement does not change)

Notes:

  • setting weights requires two or more targets; a single-target cluster rejects them but can clear existing weights;
  • with fewer than two active targets (others in maintenance), weights are accepted with a warning and no rebalance;
  • setting weights on an unweighted cluster requires a weight for every target, either explicitly or via rest=WEIGHT;
  • rest=WEIGHT covers all unlisted targets, including those in maintenance; explicit assignments win regardless of argument order;
  • proportional weights (e.g., 1,2,3 => 10,20,30) update the cluster map without rebalancing;
  • a target joining a weighted cluster gets the (rounded) mean weight of active targets;
  • clearing weights is rejected while any bucket has placement.weighting=uniform (reset it first);
  • ais show cluster shows a WEIGHT column when the cluster is weighted;
  • ais cluster placement show, ais show placement, and ais show cluster placement show the same weights and active-target shares.

Examples

For a large cluster, assign a default and override selected targets:

$ ais cluster placement set-weights t[abc]=123 rest=456
$ ais cluster placement set-weights rest=456
$ ais cluster placement show
Placement: uniform (target weights are not set)
$ ais cluster placement set-weights t[KbfnWcPR]=1 t[pRvLgrbi]=2 t[XZqbnctT]=3 t[vYFzhmPN]=4
Started rebalance "g12" (to monitor, run 'ais show rebalance').
$ ais cluster placement show
TARGET       WEIGHT  SHARE
t[KbfnWcPR]  1       10.0%
t[XZqbnctT]  3       30.0%
t[pRvLgrbi]  2       20.0%
t[vYFzhmPN]  4       40.0%
$ ais cluster placement set-weights t[KbfnWcPR]=10 t[pRvLgrbi]=20 t[XZqbnctT]=30 t[vYFzhmPN]=40
Placement weights updated (no rebalance required)
$ ais bucket props set ais://abc placement.weighting=uniform
Bucket props successfully updated.
$ ais cluster placement clear-weights
Error: cannot clear placement weights: bucket ais://abc has placement.weighting="uniform" - reset it first
$ ais bucket props set ais://abc placement.weighting=""
Bucket props successfully updated.
$ ais cluster placement clear-weights
Started rebalance "g13" (to monitor, run 'ais show rebalance').

See also: Placement weights.

Reset (ie., zero out) stats counters and other metrics

ais cluster reset-stats

Example and usage

$ ais cluster reset-stats --help
NAME:
   ais cluster reset-stats - reset cluster or node stats (all cumulative metrics or only errors)
USAGE:
   ais cluster reset-stats [NODE_ID] [command options]
OPTIONS:
   --errors-only  reset only error counters
   --help, -h     show help

Let’s go ahead and reset all error counters:

$ ais cluster reset-stats --errors-only
Cluster error metrics successfully reset

Reload backend credentials

The ais cluster reload-backend-creds command provides for adding new or updating existing backend credentials at runtime.

This improvement addresses a common scenario we encountered prior to version 3.26:

  • A new potential user requests access to a given AIS cluster.
  • The user already has an S3 bucket (or it could be a GCP, Azure, or OCI bucket).
  • We verify that the cluster has network access to the user’s bucket.
  • We need to add the user’s credentials to allow AIS nodes to access the bucket.

Before version 3.26, the final step required a cluster restart. But now, with reload-backend-creds, you can seamlessly add or update credentials without any downtime.

$ ais cluster reload-backend-creds --help
NAME:
   ais cluster reload-backend-creds - Reload (updated) backend credentials
USAGE:
   ais cluster reload-backend-creds [PROVIDER] [command options]
OPTIONS:
   --help, -h  Show help

Download log archive

The command is ‘ais cluster download-logs’ or, same, ‘ais log get cluster’.

NAME:
   ais cluster download-logs - Download log archives from all clustered nodes (one TAR.GZ per node),
   e.g.:
      - 'ais download-logs /tmp/www'      - save log archives to /tmp/www directory
      - 'ais download-logs --severity w'  - errors and warnings to /tmp directory
   see related:
      - 'ais log get --help'
USAGE:
   ais cluster download-logs [OUT_DIR] [command options]
OPTIONS:
   severity   Log severity is either 'i' or 'info' (default, can be omitted), or 'error', whereby error logs contain
              only errors and warnings, e.g.: '--severity info', '--severity error', '--severity e'
   help, h    Show help