Troubleshooting index lifecycle management errors
editTroubleshooting index lifecycle management errors
editWhen ILM executes a lifecycle policy, it’s possible for errors to occur
while performing the necessary index operations for a step.
When this happens, ILM moves the index to an ERROR
step.
If ILM cannot resolve the error automatically, execution is halted
until you resolve the underlying issues with the policy, index, or cluster.
For example, you might have a shrink-index
policy that shrinks an index to four shards once it
is at least five days old:
response = client.ilm.put_lifecycle( policy: 'shrink-index', body: { policy: { phases: { warm: { min_age: '5d', actions: { shrink: { number_of_shards: 4 } } } } } } ) puts response
PUT _ilm/policy/shrink-index { "policy": { "phases": { "warm": { "min_age": "5d", "actions": { "shrink": { "number_of_shards": 4 } } } } } }
There is nothing that prevents you from applying the shrink-index
policy to a new
index that has only two shards:
response = client.indices.create( index: 'my-index-000001', body: { settings: { 'index.number_of_shards' => 2, 'index.lifecycle.name' => 'shrink-index' } } ) puts response
PUT /my-index-000001 { "settings": { "index.number_of_shards": 2, "index.lifecycle.name": "shrink-index" } }
After five days, ILM attempts to shrink my-index-000001
from two shards to four shards.
Because the shrink action cannot increase the number of shards, this operation fails
and ILM moves my-index-000001
to the ERROR
step.
You can use the ILM Explain API to get information about what went wrong:
response = client.ilm.explain_lifecycle( index: 'my-index-000001' ) puts response
GET /my-index-000001/_ilm/explain
Which returns the following information:
{ "indices" : { "my-index-000001" : { "index" : "my-index-000001", "managed" : true, "index_creation_date_millis" : 1541717265865, "time_since_index_creation": "5.1d", "policy" : "shrink-index", "lifecycle_date_millis" : 1541717265865, "age": "5.1d", "phase" : "warm", "phase_time_millis" : 1541717272601, "action" : "shrink", "action_time_millis" : 1541717272601, "step" : "ERROR", "step_time_millis" : 1541717272688, "failed_step" : "shrink", "step_info" : { "type" : "illegal_argument_exception", "reason" : "the number of target shards [4] must be less that the number of source shards [2]" }, "phase_execution" : { "policy" : "shrink-index", "phase_definition" : { "min_age" : "5d", "actions" : { "shrink" : { "number_of_shards" : 4 } } }, "version" : 1, "modified_date_in_millis" : 1541717264230 } } } }
The policy being used to manage the index: |
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The index age: 5.1 days |
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The phase the index is currently in: |
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The current action: |
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The step the index is currently in: |
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The step that failed to execute: |
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The type of error and a description of that error. |
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The definition of the current phase from the |
To resolve this, you could update the policy to shrink the index to a single shard after 5 days:
response = client.ilm.put_lifecycle( policy: 'shrink-index', body: { policy: { phases: { warm: { min_age: '5d', actions: { shrink: { number_of_shards: 1 } } } } } } ) puts response
PUT _ilm/policy/shrink-index { "policy": { "phases": { "warm": { "min_age": "5d", "actions": { "shrink": { "number_of_shards": 1 } } } } } }
Retrying failed lifecycle policy steps
editOnce you fix the problem that put an index in the ERROR
step,
you might need to explicitly tell ILM to retry the step:
POST /my-index-000001/_ilm/retry
ILM subsequently attempts to re-run the step that failed. You can use the ILM Explain API to monitor the progress.
Common ILM setting issues
editHow min_age
is calculated
editWhen setting up an ILM policy or automating rollover with ILM, be aware that min_age
can be relative to either the rollover time or the index creation time.
If you use ILM rollover, min_age
is calculated relative to the time the index was rolled over. This is because the rollover API generates a new index and updates the age
of the previous index to reflect the rollover time. If the index hasn’t been rolled over, then the age
is the same as the creation_date
for the index.
You can override how min_age
is calculated using the index.lifecycle.origination_date
and index.lifecycle.parse_origination_date
ILM settings.
Common ILM errors
editHere’s how to resolve the most common errors reported in the ERROR
step.
Problems with rollover aliases are a common cause of errors. Consider using data streams instead of managing rollover with aliases.
Rollover alias [x] can point to multiple indices, found duplicated alias [x] in index template [z]
editThe target rollover alias is specified in an index template’s index.lifecycle.rollover_alias
setting.
You need to explicitly configure this alias one time when you
bootstrap the initial index.
The rollover action then manages setting and updating the alias to
roll over to each subsequent index.
Do not explicitly configure this same alias in the aliases section of an index template.
index.lifecycle.rollover_alias [x] does not point to index [y]
editEither the index is using the wrong alias or the alias does not exist.
Check the index.lifecycle.rollover_alias
index setting.
To see what aliases are configured, use _cat/aliases.
Setting [index.lifecycle.rollover_alias] for index [y] is empty or not defined
editThe index.lifecycle.rollover_alias
setting must be configured for the rollover action to work.
Update the index settings to set index.lifecycle.rollover_alias
.
Alias [x] has more than one write index [y,z]
editOnly one index can be designated as the write index for a particular alias.
Use the aliases API to set is_write_index:false
for all but one index.
index name [x] does not match pattern ^.*-\d+
editThe index name must match the regex pattern ^.*-\d+
for the rollover action to work.
The most common problem is that the index name does not contain trailing digits.
For example, my-index
does not match the pattern requirement.
Append a numeric value to the index name, for example my-index-000001
.
CircuitBreakingException: [x] data too large, data for [y]
editThis indicates that the cluster is hitting resource limits.
Before continuing to set up ILM, you’ll need to take steps to alleviate the resource issues. For more information, see Circuit breaker errors.
High disk watermark [x] exceeded on [y]
editThis indicates that the cluster is running out of disk space. This can happen when you don’t have index lifecycle management set up to roll over from hot to warm nodes.
Consider adding nodes, upgrading your hardware, or deleting unneeded indices.
security_exception: action [<action-name>] is unauthorized for user [<user-name>] with roles [<role-name>], this action is granted by the index privileges [manage_follow_index,manage,all]
editThis indicates the ILM action cannot be executed because the user used by ILM to perform the action doesn’t have the proper privileges. This can happen when user’s privileges has been dropped after updating the ILM policy. ILM actions are run as though they were performed by the last user who modify the policy. The account used to create or modify the policy from should have permissions to perform all operations that are part of that policy.