Querying Configuration Parameters

Function

This API is used to query the configuration parameters of a DCS instance.

URI

GET /v1.0/{project_id}/instances/{instance_id}/configs

Table 1 describes the parameters.

**Table 1** Parameter description
Parameter	Type	Mandatory	Description
project_id	String	Yes	Project ID. For details on how to obtain the value of this parameter, see Obtaining a Project ID.
instance_id	String	Yes	ID of the instance to be queried.

Request

Request parameters

None

Example request

GET https://{dcs_endpoint}/v1.0/{project_id}/instances/{instance_id}/configs

Response

Response parameters

Table 2 describes the response parameters.

**Table 2** Parameter description
Parameter	Type	Description
status	String	Current status of a DCS instance.
instance_id	String	DCS instance ID.
redis_config	Array	Array of configuration items of the DCS instance. For details, see Table 3.
config_status	String	DCS instance status that is being modified or has been modified. Options: UPDATING FAILURE SUCCESS
config_time	String	Time at which the DCS instance is operated on. For example, 2017-03-31T12:24:46.297Z.
cluster_v1	Boolean	Instance type. If true is returned, the instance is a Proxy Cluster DCS Redis 3.0 instance. If false is returned, the instance is not a Proxy Cluster DCS Redis 3.0 instance.

**Table 3** redis_config parameter description
Parameter	Type	Description
description	String	Configuration item description.
param_id	String	Configuration parameter ID. For the possible values, see the Parameter ID column in Table 4.
param_name	String	Configuration parameter name. For the possible values, see the Parameter Name column in Table 4.
param_value	String	Configuration parameter value.
default_value	String	Default value of the configuration parameter. For the possible values, see the Default Value column in Table 4.
value_type	String	Type of the configuration parameter value. For the possible values, see the Value Type column in Table 4.
value_range	String	Range of the configuration parameter value. For the possible values, see the Value Range column in Table 4.
node_role	String	If null or empty is returned, the node is a default node, that is, the Redis Server node. If proxy is returned, the node is a proxy node.

Table 4 describes the configuration parameters of a DCS instance.

**Table 4** Configuration parameters of a DCS instance
Parameter ID	Parameter Name	Type	Description	Value Range	Default Value
1	timeout	Integer	Connection between the client and server (DCS instance) will be closed if the client is idle for the timeout period (measured in seconds). A timeout period of 0 seconds indicates that the timeout function is disabled.	0–7200 seconds	0
2	maxmemory-policy	String	How Redis will select what to remove when maxmemory is reached. For details about key eviction, see the Redis official website.	volatile-lru allkeys-lru volatile-random allkeys-random volatile-ttl noeviction volatile-lfu allkeys-lfu	noeviction or volatile-lru The value range and default value depend on the instance version and type.
3	hash-max-ziplist-entries	Integer	When the number of entries in hashes is less than the value of this parameter, hashes are encoded using ziplist to save memory.	1–10,000	512
4	hash-max-ziplist-value	Integer	When the biggest entry in hashes does not exceed the length threshold indicated by this parameter, hashes are encoded using ziplist to save memory.	1–10,000	64
5	list-max-ziplist-entries	Integer	When the number of entries in lists is less than the value of this parameter, lists are encoded using ziplist to save memory.	1–10,000	512
6	list-max-ziplist-value	Integer	When the biggest entry in lists does not exceed the length threshold indicated by this parameter, lists are encoded using ziplist to save memory.	1–10,000	64
7	set-max-intset-entries	Integer	When a set is composed entirely of strings and the number of integers does not exceed the length threshold indicated by this parameter, the set is encoded using intset to save memory.	1–10,000	512
8	zset-max-ziplist-entries	Integer	When the number of entries in sorted sets is less than the value of this parameter, sorted sets are encoded using a memory efficient data structure.	1–10,000	128
9	zset-max-ziplist-value	Integer	When the biggest entry in sorted sets does not exceed the length threshold indicated by this parameter, sorted sets are encoded using ziplist to save memory.	1–10,000	64
10	latency-monitor-threshold	IntegerInteger	The minimum amount of latency that will be logged as latency spikes If this parameter is set to 0, latency monitoring is disabled. If this parameter is set to a value greater than 0, all events blocking the server for a time greater than the configured value will be logged. By running the LATENCY command, you can perform operations related to latency monitoring, such as obtaining statistical data, and configuring and enabling latency monitoring. For more information about the latency-monitor-threshold, visit the Redis official website.	0–86,400,000 ms	0
11	maxclients	Integer	The maximum number of clients allowed to be concurrently connected to a DCS instance.	1000–50,000	10,000
12	reserved-memory	Integer	Reserved memory, which is the number of megabytes reserved for the backend to perform internal processing such as persistence and master/standby replication. This parameter is available only for master/standby instances. The size of the reserved memory can be adjusted, but must be in the value range described in the next column. For more information about maximum available memory of each instance type, see Distributed Cache Service User Guide.	0% to 50% of maximum memory space initially available to the instance and below the current free memory space. Unit: MB.	0
13	notify-keyspace-events	String	Keyspace event notification. If this parameter is configured, the Redis Sub/Pub feature will allow clients to receive an event when a Redis data set is modified.	If the parameter value contains multiple characters, keyspace event notification is enabled and each character identifies a class of keyspace events for which Redis will send notifications. K: Keyspace events, published with the __keyspace@__ prefix E: Keyevent events, published with the __keyevent@__ prefix g: Generic commands (non-type specific) such as DEL, EXPIRE, and RENAME $: String commands l: List commands s: Set commands h: Hash commands z: Sorted set commands x: Expired events (events generated every time a key expires) e: Evicted events (events generated when a key is evicted for maxmemory) For more information, see the following note.	Ex
14	repl-backlog-size	Integer	The replication backlog size in bytes. The backlog is a buffer that accumulates replica data when replicas are disconnected from the master. When a replica reconnects, a partial synchronization is performed to synchronize the data that was missed while replicas were disconnected.	16,384–1,073,741,824	1,048,576
15	repl-backlog-ttl	Integer	The amount of time, in seconds, before the backlog buffer is released, starting from the last a replica was disconnected. The value 0 indicates that the backlog is never released.	0–604,800	3600
16	appendfsync	String	Controls how often fsync() transfers cached data to the disk. Note that some OSs will perform a complete data transfer but some others only make a "best-effort" attempt.	Redis calls fsync() in one of the following ways: no: fsync() is never called. The OS will flush data when it is ready. This mode offers the highest performance. always: fsync() is called after every write to the AOF. This mode is very slow, but also very safe. everysec: fsync() is called once per second. This mode provides a compromise between safety and performance.	everysec
17	appendonly	String	Indicates whether to log each modification of the instance. By default, data is written to disks asynchronously in Redis. If this function is disabled, recently-generated data might be lost in the event of a power failure.	yes,no	yes
18	slowlog-log-slower-than	Integer	Redis uses the slow log to record queries that exceed a specified execution time. slowlog-log-slower-than is the maximum time allowed, in microseconds, for command execution. If this threshold is exceeded, Slow Log will record the command.	0–1,000,000	10,000
19	slowlog-max-len	Integer	The maximum allowed length of the Redis Slow Log logs. Slow Log consumes memory, but you can reclaim this memory by running the SLOWLOG RESET command.	0–1000	128
20	lua-time-limit	Integer	The maximum time allowed for executing a Lua script, in milliseconds.	100–5000	5000
21	repl-timeout	Integer	Replication timeout, in seconds.	30–3600	60
22	proto-max-bulk-len	Integer	The maximum size (in bytes) of a single element request.	1,048,576–536,870,912	536,870,912
23	master-read-only	String	Sets the instance to be read-only. All write operations will fail.	yes,no	no
24	client-output-buffer-slave-soft-limit	Integer	Soft limit (in bytes) on the output buffer of replica clients. Once the output buffer exceeds the soft limit and continuously remains above the limit for the time specified by the client-output-buffer-limit-slave-soft-seconds parameter, the client is disconnected.	0–134,217,728	13,421,772
25	client-output-buffer-slave-hard-limit	Integer	Hard limit (in bytes) on the output buffer of replica clients. Once the output buffer exceeds the hard limit, the client is immediately disconnected.	0–134,217,728	13,421,772
26	client-output-buffer-limit-slave-soft-seconds	Integer	Number of seconds that the output buffer remains above client-output-buffer-slave-soft-limit before the client is disconnected.	0–60	60
30	reserved-memory-percent	Integer	Percentage of memory reserved for non-cache memory usage.	0–80	0

More about the notify-keyspace-events parameter:

Allowed characters are K, E, KE, A, g, l, s, h, z, x, e, and $. The parameter value must contain either K or E.
A is an alias for g$lshzxe and cannot be used together with any of the characters in g$lshzxe.
For example, the value Kl means that Redis will notify Pub/Sub clients about keyspace events and list commands. The value AKE means Redis will notify Pub/Sub clients about all events.

Example response

{
    "status": "RUNNING",
    "instance_id": "c08fdc6e-5c25-4185-ab57-c0a5529b727f",
    "redis_config": [
        {
            "description": "How Redis will select what to remove when maxmemory is reached, You can select among five behaviors: volatile-lru : remove the key with an expire set using an LRU algorithm allkeys-lru : remove any key according to the LRU algorithm volatile-random: remove a random key with an expire set allkeys-random: remove a random key, any key volatile-ttl : remove the key with the nearest expire time (minor TTL) noeviction : don't expire at all, just return an error on write operations",
            "param_id": 2,
            "param_name": "maxmemory-policy",
            "param_value": "noeviction",
            "default_value": "noeviction",
            "value_type": "String",
            "value_range": "volatile-lru,allkeys-lru,volatile-random,allkeys-random,volatile-ttl,noeviction"
        },
        {
            "description": "Hashes are encoded using a memory efficient data structure when they have a small number of entries",
            "param_id": 3,
            "param_name": "hash-max-ziplist-entries",
            "param_value": "512",
            "default_value": "512",
            "value_type": "Integer",
            "value_range": "1-10000"
        },
        {
            "description": "Hashes are encoded using a memory efficient data structure when the biggest entry does not exceed a given threshold",
            "param_id": 4,
            "param_name": "hash-max-ziplist-value",
            "param_value": "64",
            "default_value": "64",
            "value_type": "Integer",
            "value_range": "1-10000"
        },
        {
            "description": "Lists are encoded using a memory efficient data structure when they have a small number of entries",
            "param_id": 5,
            "param_name": "list-max-ziplist-entries",
            "param_value": "512",
            "default_value": "512",
            "value_type": "Integer",
            "value_range": "1-10000"
        },
        {
            "description": "Lists are encoded using a memory efficient data structure when the biggest entry does not exceed a given threshold",
            "param_id": 6,
            "param_name": "list-max-ziplist-value",
            "param_value": "64",
            "default_value": "64",
            "value_type": "Integer",
            "value_range": "1-10000"
        },
        {
            "description": "When a set is composed of just strings that happen to be integers in radix 10 in the range of 64 bit signed integers.",
            "param_id": 7,
            "param_name": "set-max-intset-entries",
            "param_value": "512",
            "default_value": "512",
            "value_type": "Integer",
            "value_range": "1-10000"
        },
        {
            "description": "Sorted sets are encoded using a memory efficient data structure when they have a small number of entries",
            "param_id": 8,
            "param_name": "zset-max-ziplist-entries",
            "param_value": "128",
            "default_value": "128",
            "value_type": "Integer",
            "value_range": "1-10000"
        },
        {
            "description": "Sorted sets are encoded using a memory efficient data structure when the biggest entry does not exceed a given threshold",
            "param_id": 9,
            "param_name": "zset-max-ziplist-value",
            "param_value": "64",
            "default_value": "64",
            "value_type": "Integer",
            "value_range": "1-10000"
        },
        {
            "description": "Close the connection after a client is idle for N seconds (0 to disable)",
            "param_id": 1,
            "param_name": "timeout",
            "param_value": "0",
            "default_value": "0",
            "value_type": "Integer",
            "value_range": "0-7200"
        },
        {
            "description": "Only events that run in more time than the configured latency-monitor-threshold will be logged as latency spikes. If latency-monitor-threshold is set to 0, latency monitoring is disabled. If latency-monitor-threshold is set to a value greater than 0, all events blocking the server for a time equal to or greater than the configured latency-monitor-threshold will be logged.",
            "param_id": 10,
            "param_name": "latency-monitor-threshold",
            "param_value": "0",
            "default_value": "0",
            "value_type": "Integer",
            "value_range": "0-86400000"
        },
        {
            "description": "The total memory, in bytes, reserved for non-data usage.",
            "param_id": 12,
            "param_name": "reserved-memory",
            "param_value": "0",
            "default_value": "0",
            "value_type": "Integer",
            "value_range": "0-6553"
        },
        {
            "description": "Redis can notify Pub or Sub clients about events happening in the key space",
            "param_id": 13,
            "param_name": "notify-keyspace-events",
            "param_value": null,
            "default_value": null,
            "value_type": "regular",
            "value_range": "([KE]+([A]|[g$lshzxe]+)){0,11}"
        }
    ],
    "config_status": "SUCCESS",
    "config_time": ""
}