Troubleshooting ¶

First of all, see a similar guide in the Tarantool manual. Below you can find other Cartridge-specific problems considered.

Contents

Troubleshooting

Problems with replica ¶

Examples:

Missing .xlog file between LSN 5137088 {1: 240379, 2: 4750534, 5: 146175} and 5137379 {1: 240379, 2: 4750825, 5: 146175} which means that master lost one or more of their xlog files, please check it
Duplicate key exists in unique index "primary" in space "T1" with old tuple

Solution:

If you have some replication conflicts and issues that you don’t know how to deal with, try to rebootstrap the replica.

(!) Make sure that you have your data safe on the master before rebootstrap.

Stop the instance
Delete snapshots and xlogs
Preserve cluster-wide config (config dir)
Restart the instance

Editing clusterwide configuration in WebUI returns an error ¶

Examples:

NetboxConnectError: "localhost:3302": Connection refused;
Prepare2pcError: Instance state is OperationError, can't apply config in this state.

The root problem: all cluster instances are equal, and all of them store a copy of clusterwide configuration, which must be the same. If an instance degrades (can’t accept new configuration) – the quorum is lost. This prevents further configuration modifications to avoid inconsistency.

But sometimes inconsistency is needed to repair the system, at least partially and temporarily. It can be achieved by disabling degraded instances.

Solution:

Connect to the console of the alive instance.

tt connect /var/run/tarantool/<app-name>.<instance-name>.control

Inspect what’s going on.

cartridge = require('cartridge')
report = {}
for _, srv in pairs(cartridge.admin_get_servers()) do
    report[srv.uuid] = {uri = srv.uri, status = srv.status, message = srv.message}
end
return report

If you’re ready to proceed, run the following snippet. It’ll disable all instances which are not healthy. After that, you can use the WebUI as usual.

disable_list = {}
for uuid, srv in pairs(report) do
    if srv.status ~= 'healthy' then
       table.insert(disable_list, uuid)
    end
end
return cartridge.admin_disable_servers(disable_list)

When it’s necessary to bring disabled instances back, re-enable them in a similar manner:

cartridge = require('cartridge')
enable_list = {}
for _, srv in pairs(cartridge.admin_get_servers()) do
    if srv.disabled then
       table.insert(enable_list, srv.uuid)
    end
end
return cartridge.admin_enable_servers(enable_list)

An instance is stuck in the ConnectingFullmesh state upon restart ¶

Example:

The root problem: after restart, the instance tries to connect to all its replicas and remains in the ConnectingFullmesh state until it succeeds. If it can’t (due to replica URI unavailability or for any other reason) – it’s stuck forever.

Solution:

Set the replication_connect_quorum option to zero. It may be accomplished in two ways:

By restarting it with the corresponding option set (in environment variables or in the instance configuration file);

Or without restart – by running the following one-liner:

echo "box.cfg({replication_connect_quorum = 0})" | tt connect \
/var/run/tarantool/<app-name>.<instance-name>.control -f -

I want to run an instance with a new advertise_uri ¶

The root problem: advertise_uri parameter is persisted in the clusterwide configuration. Even if it changes upon restart, the rest of the cluster keeps using the old one, and the cluster may behave in an odd way.

Solution:

The clusterwide configuration should be updated.

Make sure all instances are running and not stuck in the ConnectingFullmesh state (see above).
Make sure all instances have discovered each other (i.e. they look healthy in the WebUI).

Run the following snippet in the Tarantool console. It’ll prepare a patch for the clusterwide configuration.

cartridge = require('cartridge')
members = require('membership').members()

edit_list = {}
changelog = {}
for _, srv in pairs(cartridge.admin_get_servers()) do
    for _, m in pairs(members) do
        if m.status == 'alive'
        and m.payload.uuid == srv.uuid
        and m.uri ~= srv.uri
        then
            table.insert(edit_list, {uuid = srv.uuid, uri = m.uri})
            table.insert(changelog, string.format('%s -> %s (%s)', srv.uri, m.uri, m.payload.alias))
            break
        end
    end
end
return changelog

As a result you’ll see a brief summary like the following one:

localhost:3301> return changelog
---
- - localhost:13301 -> localhost:3301 (srv-1)
  - localhost:13302 -> localhost:3302 (srv-2)
  - localhost:13303 -> localhost:3303 (srv-3)
  - localhost:13304 -> localhost:3304 (srv-4)
  - localhost:13305 -> localhost:3305 (srv-5)
...

Finally, apply the patch:

cartridge.admin_edit_topology({servers = edit_list})

The cluster is doomed, I’ve edited the config manually. How do I reload it?¶

Warning

Please be aware that it’s quite risky and you know what you’re doing. There’s some useful information about clusterwide configuration anatomy and “normal” management API.

But if you’re still determined to reload the configuration manually, you can do (in the Tarantool console):

function reload_clusterwide_config()
    local changelog = {}

    local ClusterwideConfig = require('cartridge.clusterwide-config')
    local confapplier = require('cartridge.confapplier')

    -- load config from filesystem
    table.insert(changelog, 'Loading new config...')

    local cfg, err = ClusterwideConfig.load('./config')
    if err ~= nil then
        return changelog, string.format('Failed to load new config: %s', err)
    end

    -- check instance state
    table.insert(changelog, 'Checking instance config state...')

    local roles_configured_state = 'RolesConfigured'
    local connecting_fullmesh_state = 'ConnectingFullmesh'

    local state = confapplier.wish_state(roles_configured_state, 10)

    if state == connecting_fullmesh_state then
        return changelog, string.format(
            'Failed to reach %s config state. Stuck in %s. ' ..
                'Call "box.cfg({replication_connect_quorum = 0})" in instance console and try again',
            roles_configured_state, state
        )
    end

    if state ~= roles_configured_state then
        return changelog, string.format(
            'Failed to reach %s config state. Stuck in %s',
            roles_configured_state, state
        )
    end

    -- apply config changes
    table.insert(changelog, 'Applying config changes...')

    cfg:lock()
    local ok, err = confapplier.apply_config(cfg)
    if err ~= nil then
        return changelog, string.format('Failed to apply new config: %s', err)
    end

    table.insert(changelog, 'Cluster-wide configuration was successfully updated')

    return changelog
end

reload_clusterwide_config()

This snippet reloads the configuration on a single instance. All other instances continue operating as before.

Note

If further configuration modifications are made with a two-phase commit (e.g. via the WebUI or with the Lua API), the active configuration of an active instance will be spread across the cluster.

Repairing cluster using Cartridge CLI repair command ¶

Cartridge CLI has repair command since version 2.3.0.

It can be used to get current topology, remove instance from cluster, change replicaset leader or change instance advertise URI.

Note

cartridge repair patches the cluster-wide configuration files of application instances placed ON THE LOCAL MACHINE. It means that running cartridge repair on all machines is user responsibility.

Note

It’s not enough to apply new configuration: the configuration should be reloaded by the instance. If your application uses cartridge >= 2.0.0, you can simply use --reload flag to reload configuration. Otherwise, you need to restart instances or reload configuration manually.

Changing instance advertise URI ¶

To change instance advertise URI you have to perform these actions:

Start instance with a new advertise URI. The easiest way is to change advertise_uri value in the instance configuration file).
Make sure instances are running and not stuck in the ConnectingFullmesh state (see above).
Get instance UUID:
- open server details tab in WebUI;
- call cartridge repair list-topology --name <app-name> and find desired instance UUID:
- get instance box.info().uuid:
```
echo "return box.info().uuid" | tt connect \
/var/run/tarantool/<app-name>.<instance-name>.control -f -
```
Now we need to update instance advertise URI in all instances cluster-wide configuration files on each machine. Run cartridge repair set-advertise-uri with --dry-run flag on each machine to check cluster-wide config changes computed by cartridge-cli:
```
cartridge repair set-advertise-uri \
  --name myapp \
  --dry-run \
  <instance-uuid> <new-advertise-uri>
```
Run cartridge repair set-advertise-uri without --dry-run flag on each machine to apply config changes computed by cartridge-cli. If your application uses cartridge >= 2.0.0, you can specify --reload flag to load new cluter-wide configuration on instances. Otherwise, you need to restart instances or reload configuration manually.
```
cartridge repair set-advertise-uri \
  --name myapp \
  --verbose \
  --reload \
  <instance-uuid> <new-advertise-uri>
```

Changing replicaset leader ¶

You can change replicaset leader using cartridge repair command.

Get replicaset UUID and new leader UUID (in WebUI or by calling cartridge repair list-topology --name <app-name>).
Now we need to update cluster-wide config for all instances on each machine. Run cartridge repair set-leader with --dry-run flag on each machine to check cluster-wide config changes computed by `` cartridge-cli``:
```
cartridge repair set-leader \
  --name myapp \
  --dry-run \
  <replicaset-uuid> <instance-uuid>
```
Run cartridge repair set-advertise-uri without --dry-run flag on each machine to apply config changes computed by cartridge-cli. If your application uses cartridge >= 2.0.0, you can specify --reload flag to load new cluter-wide configuration on instances. Otherwise, you need to restart instances or reload configuration manually.
```
cartridge repair set-leader \
  --name myapp \
  --verbose \
  --reload \
  <replicaset-uuid> <instance-uuid>
```

Removing instance from the cluster ¶

You can remove instance from cluster using cartridge repair command.

Get instance UUID:
- open server details tab in WebUI;
- call cartridge repair list-topology --name <app-name> and find desired instance UUID:
- get instance box.info().uuid:
```
echo "return box.info().uuid" | tt connect \
/var/run/tarantool/<app-name>.<instance-name>.control -f -
```
Now we need to update cluster-wide config for all instances on each machine. Run cartridge repair remove-instance with --dry-run flag on each machine to check cluster-wide config changes computed by cartridge-cli:
```
cartridge repair remove-instance \
  --name myapp \
  --dry-run \
  <replicaset-uuid>
```
Run cartridge repair remove-instance without --dry-run flag on each machine to apply config changes computed by cartridge-cli. If your application uses cartridge >= 2.0.0, you can specify --reload flag to load new cluter-wide configuration on instances. Otherwise, you need to restart instances or reload configuration manually.
```
cartridge repair set-leader \
  --name myapp \
  --verbose \
  --reload \
  <replicaset-uuid> <instance-uuid>
```

Broken failover promote in Cartridge 2.7.7/2.7.8 ¶

When updating on Cartridge 2.7.7/2.7.8 while trying to promote a replica you can see an error like this: Cannot appoint non-electable instance.

This is a known bug in Cartridge 2.7.7/2.7.8, which is fixed in Cartridge 2.7.9.

To fix this issue, you need to update Cartridge to version 2.7.9 or higher.

Or you can use the following workaround:

require('cartridge.lua-api.topology').set_electable_servers({uuid1, uuid2, ... uuidN}) -- list all of your uuids here

A ‘Connection refused’ error in unconfigured instance since 2.7.4 ¶

Before v2.7.4, an unconfigured instance was bound to the 0.0.0.0 interface. Given that 0.0.0.0 accepts connections on any IP address assigned to the machine, this might impose additional security risks.

With v2.7.4 version, an unconfigured instance resolves the advertise_uri host and binds to it. You can check that the instance’s advertise_uri is resolved to a network interface (not loopback) as follows:

dig +short place_advertise_uri_here

‘Address already in use’ errors ¶

There are the following known ‘Address already in use’ errors:

CartridgeCfgError: Socket bind error (<port>/udp): Address already in use
HttpInitError: <…> Can’t create tcp_server: Address already in use
RemoteControlError: Can’t start server on <host>:<port>: Address already in use

You can see these errors in Tarantool logs only. The reason causing these errors is that Tarantool cannot use the binary (for example, 3301) or HTTP (for example, 8081) port. As a result, the instance cannot be configured and fails with an error.

To fix an error, follow the steps below:

Determine which port is busy.
Use the lsof command to determine the application that uses this port:
```
sudo lsof -i :<port>
```
Note that without sudo you can see only the current user’s processes.

Determine the connection type, for example:

# An outgoing connection on the 50858 port
TCP 192.168.100.17:50858->google.com:https (ESTABLISHED)

# Waiting for incoming requests on the 3301 port.
TCP localhost:3301 (LISTEN)

For an outgoing connection, you need to adjust the port range used to choose the local port, for example:
```
echo "32768 61000" > /proc/sys/net/ipv4/ip_local_port_range
/etc/rc.d/init.d/network restart
```
For an incoming connection, do one of the following:
- For Google Chrome, etcd, nginx, or other application, you need to adjust settings to release a busy port.
- For Tarantool, you might have an incorrect cluster topology or there might be several clusters running simultaneously. In this case, please contact Tarantool support.

Troubleshooting ¶

Problems with replica ¶

Editing clusterwide configuration in WebUI returns an error ¶

An instance is stuck in the ConnectingFullmesh state upon restart ¶

I want to run an instance with a new advertise_uri ¶

The cluster is doomed, I’ve edited the config manually. How do I reload it?¶

Repairing cluster using Cartridge CLI repair command ¶

Changing instance advertise URI ¶

Changing replicaset leader ¶

Removing instance from the cluster ¶

Broken failover promote in Cartridge 2.7.7/2.7.8 ¶

A ‘Connection refused’ error in unconfigured instance since 2.7.4 ¶

‘Address already in use’ errors ¶

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