Run-time Configuration
Passing configuration options on module load
Passing configuration options is done by appending arguments after the --loadmodule argument when starting a server from the command line or after the loadmodule directive in a Redis config file. For example:
In redis.conf:
loadmodule ./redisgraph.so OPT1 VAL1
From the command line:
$ redis-server --loadmodule ./redisgraph.so OPT1 VAL1
Passing configuration options at run-time
RedisGraph exposes the GRAPH.CONFIG endpoint to allowing for the setting and retrieval of configurations at run-time.
To set a config, simply run:
GRAPH.CONFIG SET OPT1 VAL1
Similarly, the current configurations can be retrieved using the syntax:
GRAPH.CONFIG GET OPT1
GRAPH.CONFIG GET *
RedisGraph configuration options
| Configuration | Load-time | Run-time |
|---|---|---|
| THREAD_COUNT | :white_check_mark: | :white_large_square: |
| CACHE_SIZE | :white_check_mark: | :white_large_square: |
| OMP_THREAD_COUNT | :white_check_mark: | :white_large_square: |
| NODE_CREATION_BUFFER | :white_check_mark: | :white_large_square: |
| MAX_QUEUED_QUERIES | :white_check_mark: | :white_check_mark: |
| TIMEOUT | :white_check_mark: | :white_check_mark: |
| RESULTSET_SIZE | :white_check_mark: | :white_check_mark: |
| QUERY_MEM_CAPACITY | :white_check_mark: | :white_check_mark: |
THREAD_COUNT
The number of threads in RedisGraph's thread pool. This is equivalent to the maximum number of queries that can be processed concurrently.
Default
THREAD_COUNT defaults to the system's hardware threads (logical cores).
Example
$ redis-server --loadmodule ./redisgraph.so THREAD_COUNT 4
CACHE_SIZE
The max number of queries for RedisGraph to cache. When a new query is encountered and the cache is full, meaning the cache has reached the size of CACHE_SIZE, it will evict the least recently used (LRU) entry.
Default
CACHE_SIZE default value is 25.
Example
$ redis-server --loadmodule ./redisgraph.so CACHE_SIZE 10
OMP_THREAD_COUNT
The maximum number of threads that OpenMP may use for computation per query. These threads are used for parallelizing GraphBLAS computations, so may be considered to control concurrency within the execution of individual queries.
Default
OMP_THREAD_COUNT is defined by GraphBLAS by default.
Example
$ redis-server --loadmodule ./redisgraph.so OMP_THREAD_COUNT 1
NODE_CREATION_BUFFER
The node creation buffer is the number of new nodes that can be created without resizing matrices. For example, when set to 16,384, the matrices will have extra space for 16,384 nodes upon creation. Whenever the extra space is depleted, the matrices' size will increase by 16,384.
Reducing this value will reduce memory consumption, but cause performance degradation due to the increased frequency of matrix resizes.
Conversely, increasing it might improve performance for write-heavy workloads but will increase memory consumption.
If the passed argument was not a power of 2, it will be rounded to the next-greatest power of 2 to improve memory alignment.
MAX_QUEUED_QUERIES
Setting the maximum number of queued queries allows the server to reject incoming queries with the error message Max pending queries exceeded. This reduces the memory overhead of pending queries on an overloaded server and avoids congestion when the server processes its backlog of queries.
Default
MAX_QUEUED_QUERIES is effectively unlimited by default (config value of UINT64_MAX).
Example
$ redis-server --loadmodule ./redisgraph.so MAX_QUEUED_QUERIES 500
$ redis-cli GRAPH.CONFIG SET MAX_QUEUED_QUERIES 500
Default
NODE_CREATION_BUFFER is 16,384 by default.
Minimum
The minimum value for NODE_CREATION_BUFFER is 128. Values lower than this will be accepted as arguments, but will internally be converted to 128.
Example
$ redis-server --loadmodule ./redisgraph.so NODE_CREATION_BUFFER 200
TIMEOUT
Timeout is a flag that specifies the maximum runtime for read queries in milliseconds. This configuration will not be respected by write queries, to avoid leaving the graph in an inconsistent state.
Default
TIMEOUT is off by default (config value of 0).
Example
$ redis-server --loadmodule ./redisgraph.so TIMEOUT 1000
RESULTSET_SIZE
Result set size is a limit on the number of records that should be returned by any query. This can be a valuable safeguard against incurring a heavy IO load while running queries with unknown results.
Default
RESULTSET_SIZE is unlimited by default (negative config value).
Example
127.0.0.1:6379> GRAPH.CONFIG SET RESULTSET_SIZE 3
OK
127.0.0.1:6379> GRAPH.QUERY G "UNWIND range(1, 5) AS x RETURN x"
1) 1) "x"
2) 1) 1) (integer) 1
2) 1) (integer) 2
3) 1) (integer) 3
3) 1) "Cached execution: 0"
2) "Query internal execution time: 0.445790 milliseconds"
QUERY_MEM_CAPACITY
Setting the memory capacity of a query allows the server to kill queries that are consuming too much memory and return with the error message Query's mem consumption exceeded capacity. This helps to avoid scenarios when the server becomes unresponsive due to an unbounded query exhausting system resources.
The configuration argument is the maximum number of bytes that can be allocated by any single query.
Default
QUERY_MEM_CAPACITY is unlimited by default; this default can be restored by setting QUERY_MEM_CAPACITY to zero or a negative value.
Example
$ redis-server --loadmodule ./redisgraph.so QUERY_MEM_CAPACITY 1048576 // 1 megabyte limit
$ redis-cli GRAPH.CONFIG SET QUERY_MEM_CAPACITY 1048576
Query Configurations
The query timeout configuration may also be set per query in the form of additional arguments after the query string. This configuration is unset by default unless using a language-specific client, which may establish its own defaults.
Query Timeout
The query flag timeout allows the user to specify a timeout as described in TIMEOUT for a single query.
Example
Retrieve all paths in a graph with a timeout of 1000 milliseconds.
GRAPH.QUERY wikipedia "MATCH p=()-[*]->() RETURN p" timeout 1000