# Using Amazon Neptune slow-query logging
Identifying, debugging and optimizing a slow-running query can be difficult. When Neptune's slow-query logging is enabled, attributes of all long-running queries are automatically logged to make this process easier.
**Note**
Slow-query logging was introduced in Neptune [engine release 1.2.1.0](engine-releases-1.2.1.0.md).
You enable slow-query logging using the [neptune\$1enable\$1slow\$1query\$1log](parameters.md#parameters-db-cluster-parameters-neptune_enable_slow_query_log) DB cluster parameter. By default, this parameter is set to `disabled`. Setting it to `info` or `debug` enables slow-query logging. The `info` setting logs a few useful attributes of each slow-running query, whereas the `debug` setting logs all available attributes.
To set the threshold for what is considered a slow-running query, use the [neptune\$1slow\$1query\$1log\$1threshold](parameters.md#parameters-db-cluster-parameters-neptune_slow_query_log_threshold) DB cluster parameter to specify the number of milliseconds after which a running query is considered slow and is logged when slow-query logging is enabled. The default value is 5000 milliseconds (5 seconds).
You can set these DB cluster parameters [in the AWS Management Console](parameter-groups.md#parameters-editgroup), or using the [modify-db-cluster-parameter-group](https://docs.aws.amazon.com/cli/latest/reference/neptune/modify-db-cluster-parameter-group.html) AWS CLI command, or the [ModifyDBClusterParameterGroup](api-parameters.md#ModifyDBClusterParameterGroup) management function.
**Note**
The slow-query logging parameters are dynamic, meaning that changing their values does not require or cause a restart of your DB cluster.
## To view slow-query logs in the AWS Management Console
You can view and download slow-query logs in the AWS Management Console, as follows:
On the **Instances** page, choose a DB instance and then scroll to the **Logs** section. You can then select a log file there and then choose **Download** to download it.
## The files generated by Neptune slow-query logging
The log files generated by slow-query logging in Neptune have the following characteristics:
+ The files are encoded as UTF-8.
+ Queries and their attributes are logged in JSON form.
+ Null and empty attributes are not logged, except for `queryTime` data.
+ Logs span multiple files, the number of which varies with instance size.
+ Log entries are not in sequential order. You can use their `timestamp` values to order them.
+ To see the latest events, you may have to review all the slow-query log files.
+ Log files are rotated when they reach 100 MiB in aggregate. This limit is not configurable.
## Query attributes logged in `info` mode
The following attributes are logged for slow queries when the `neptune_enable_slow_query_log` DB cluster parameter has been set to `info`:
[\[See the AWS documentation website for more details\]](http://docs.aws.amazon.com/neptune/latest/userguide/slow-query-logs.html)
## Query attributes logged in `debug` mode
When the `neptune_enable_slow_query_log` DB cluster parameter has been set to `debug`, the following storage-counter attributes are logged in addition to the attributes that are logged as in `info` mode:
| Attribute | Description |
| --- | --- |
| `statementsScannedInAllIndexes` | Statements scanned in all indexes. |
| `statementsScannedSPOGIndex` | Statements scanned in SPOG index. |
| `statementsScannedPOGSIndex` | Statements scanned in POGS index. |
| `statementsScannedGPSOIndex` | Statements scanned in GPSO index. |
| `statementsScannedOSGPIndex` | Statements scanned in OSGP index. |
| `statementsScannedInChunk` | Statements scanned together in chunk. |
| `postFilteredStatementScans` | Statements left after post filtering after scans. |
| `distinctStatementScans` | Distinct statements scanned. |
| `statementsReadInAllIndexes` | Statements read after scan post filtering in all indexes. |
| `statementsReadSPOGIndex` | Statements read after scan post filtering in SPOG index. |
| `statementsReadPOGSIndex` | Statements read after scan post filtering in POGS index. |
| `statementsReadGPSOIndex` | Statements read after scan post filtering in GPSO index. |
| `statementsReadOSGPIndex` | Statements read after scan post filtering in OSGP index. |
| `accessPathSearches` | Number of access path searches. |
| `fullyBoundedAccessPathSearches` | Number of fully bounded key access path searches. |
| `accessPathSearchedByPrefix` | Number of access path searched by prefix. |
| `searchesWhereRecordsWereFound` | Number of searches which had 1 or more records as output. |
| `searchesWhereRecordsWereNotFound` | Number of searches which had no records as output. |
| `totalRecordsFoundInSearches` | Total records found from all searches. |
| `statementsInsertedInAllIndexes` | Number of statements inserted in all indexes. |
| `statementsUpdatedInAllIndexes` | Number of statements updated in all indexes. |
| `statementsDeletedInAllIndexes` | Number of statements deleted in all indexes. |
| `predicateCount` | Number of predicates. |
| `dictionaryReadsFromValueToIdTable` | Number of dictionary reads from value to ID table. |
| `dictionaryReadsFromIdToValueTable` | Number of dictionary reads from ID of value table. |
| `dictionaryWritesToValueToIdTable` | Number of dictionary writes to value to ID table. |
| `dictionaryWritesToIdToValueTable` | Number of dictionary writes to ID to value table. |
| `rangeCountsInAllIndexes` | Number of range counts in all indexes. |
| `deadlockCount` | Number of deadlocks in the query. |
| `singleCardinalityInserts` | Number of single cardinanity inserts performed. |
| `singleCardinalityInsertDeletions` | Number of statements deleted during single cardinality insert. |
| `sharedLocksWaitTimeMillis` | Number of milliseconds spent waiting for shared locks. |
| `exclusiveLocksWaitTimeMillis` | Number of milliseconds spent waiting for exclusive locks. |
## Example of debug logging for a slow query
The following Gremlin query could take longer to run than the threshold set for slow queries:
```
gremlin=g.V().has('code','AUS').repeat(out().simplePath()).until(has('code','AGR')).path().by('code').limit(20).fold()
```
Then, if slow-query logging was enabled in debug mode, the following attributes would be logged for the query, in a form like this:
```
{
"requestResponseMetadata": {
"requestId": "5311e493-0e98-457e-9131-d250a2ce1e12",
"requestType": "HTTP_GET",
"responseStatusCode": 200
},
"queryStats": {
"query": "gremlin=g.V().has('code','AUS').repeat(out().simplePath()).until(has('code','AGR')).path().by('code').limit(20).fold()",
"queryFingerprint": "g.V().has(string0,string1).repeat(__.out().simplePath()).until(__.has(string0,string2)).path().by(string0).limit(long0).fold()",
"queryLanguage": "Gremlin"
},
"memoryStats": {
"allocatedPermits": 20,
"approximateUsedMemoryBytes": 14838
},
"queryTimeStats": {
"startTime": "23/02/2023 11:42:52.657",
"overallRunTimeMs": 2249,
"executionTimeMs": 2229,
"serializationTimeMs": 13
},
"statementCounters": {
"read": 69979
},
"transactionCounters": {
"committed": 1
},
"concurrentExecutionStats": {
"acceptedQueryCountAtStart": 1
},
"queryBatchStats": {
"queryProcessingBatchSize": 1000,
"querySerialisationBatchSize": 1000
},
"storageCounters": {
"statementsScannedInAllIndexes": 69979,
"statementsScannedSPOGIndex": 44936,
"statementsScannedPOGSIndex": 4,
"statementsScannedGPSOIndex": 25039,
"statementsReadInAllIndexes": 68566,
"statementsReadSPOGIndex": 43544,
"statementsReadPOGSIndex": 2,
"statementsReadGPSOIndex": 25020,
"accessPathSearches": 27,
"fullyBoundedAccessPathSearches": 27,
"dictionaryReadsFromValueToIdTable": 10,
"dictionaryReadsFromIdToValueTable": 17,
"rangeCountsInAllIndexes": 4,
"sharedLocksWaitTimeMillis": 0,
"exclusiveLocksWaitTimeMillis": 0
}
}
```