searchd {
...
    query_log = /var/log/query.log
    query_log_format = sphinxql # default
...
}

Two query log formats are supported:

• sphinxql (default): Logs in SQL format. It also provides an easy way to replay logged queries.
• plain: Logs full-text queries in a simple text format. Recommended if most of your queries are primarily full-text, or if you don't care about non-full-text components of your queries, such as filtering by attributes, sorting, grouping, etc. Queries logged in the plain format cannot be replayed.

To switch between the formats, you can use the searchd setting query_log_format.

query_log_format = sphinxql # default

/* Sun Apr 28 12:38:02.808 2024 conn 2 (127.0.0.1:53228) real 0.000 wall 0.000 found 0 */ SELECT * FROM test WHERE MATCH('test') OPTION ranker=proximity;
/* Sun Apr 28 12:38:05.585 2024 conn 2 (127.0.0.1:53228) real 0.001 wall 0.001 found 0 */ SELECT * FROM test WHERE MATCH('test') GROUP BY channel_id OPTION ranker=proximity;
/* Sun Apr 28 12:40:57.366 2024 conn 4 (127.0.0.1:53256) real 0.000 wall 0.000 found 0 */  /*{
    "index" : "test",
    "query":
    {
        "match":
        {
            "*" : "test"
        }
    },
    "_source": ["f"],
    "limit": 30
} */

query_log_format = plain

[query-date] real-time wall-time [match-mode/filters-count/sort-mode total-matches (offset,limit) @groupby-attr] [table-name] {perf-stats} query

[Fri Jun 29 21:17:58 2021] 0.004 sec [all/0/rel 35254 (0,20)] [lj] [ios=6 kb=111.1 ms=0.5] test
[Fri Jun 29 21:17:58 2021] 0.004 sec [all/0/rel 35254 (0,20)] [lj] [ios=6 kb=111.1 ms=0.5 cpums=0.3] test
[Sun Apr 28 15:09:38.712 2024] 0.000 sec 0.000 sec [ext2/0/ext 0 (0,20)] [test] test
[Sun Apr 28 15:09:44.974 2024] 0.000 sec 0.000 sec [ext2/0/ext 0 (0,20) @channel_id] [test] test
[Sun Apr 28 15:24:32.975 2024] 0.000 sec 0.000 sec [ext2/0/ext 0 (0,30)] [test] {     "index" : "test",     "query":     {         "match":         {             "*" : "test"         }     },     "_source": ["f"],     "limit": 30 }

searchd {
...
    query_log = /var/log/query.log
    query_log_min_msec  = 1000
    # query_log_min_msec  = 1s
...
}

searchd {
...
    query_log = /var/log/query.log
    query_log_mode = 666
...
}

By default, Manticore search daemon logs all runtime events in a searchd.log file in the directory where searchd was started. In Linux by default, you can find the log at /var/log/manticore/searchd.log.

The log file path/name can be overridden by setting log in the searchd section of the configuration file.

searchd {
...
    log = /custom/path/to/searchd.log
...
}

• You can also use syslog as the file name. In this case, events will be sent to your server's syslog daemon.
• In some cases, you might want to use /dev/stdout as the file name. In this case, on Linux, Manticore will simply output the events. This can be useful in Docker/Kubernetes environments.

Binary logging serves as a recovery mechanism for Real-Time table data, as well as attribute updates for plain tables that would otherwise only be stored in RAM until a flush occurs. When binary logs are enabled, searchd records each transaction to the binlog file and utilizes it for recovery following an unclean shutdown. During a clean shutdown, RAM chunks are saved to disk, and all binlog files are subsequently unlinked.

By default, binary logging is enabled. On Linux systems, the default location for binlog.* files is /var/lib/manticore/data/. In RT mode, binary logs are stored in the data_dir folder, unless specified otherwise.

To disable binary logging, set binlog_path to empty:

searchd {
...
    binlog_path = # disable logging
...

Disabling binary logging can lead to better performance for Real-Time tables, but it also puts their data at risk.

You can use the following directive to set a custom path:

searchd {
...
    binlog_path = /var/data
...

When logging is enabled, each transaction committed to an RT table is written to a log file. After an unclean shutdown, logs are automatically replayed upon startup, recovering any logged changes.

During normal operation, a new binlog file is opened whenever the binlog_max_log_size limit is reached. Older, closed binlog files are retained until all transactions stored in them (from all tables) are flushed as a disk chunk. Setting the limit to 0 essentially prevents the binlog from being unlinked while searchd is running; however, it will still be unlinked upon a clean shutdown. By default, there is no limit to the log file size.

binlog_max_log_size = 16M

There are 3 different binlog flushing strategies, controlled by the binlog_flush directive:

• 0 - Flush and sync every second. This provides the best performance, but up to 1 second's worth of committed transactions may be lost in the event of a server crash or an OS/hardware crash.
• 1 - Flush and sync every transaction. This has the worst performance, but guarantees that every committed transaction's data is saved.
• 2 - Flush every transaction and sync every second. This offers good performance, and every committed transaction is guaranteed to be saved in the case of a server crash. However, up to 1 second's worth of committed transactions may be lost in the event of an OS/hardware crash.

The default mode is to flush every transaction and sync every second (mode 2).

searchd {
...
    binlog_flush = 1 # ultimate safety, low speed
...
}

During recovery after an unclean shutdown, binlogs are replayed, and all logged transactions since the last good on-disk state are restored. Transactions are checksummed, so in case of binlog file corruption, garbage data will not be replayed; such a broken transaction will be detected and will stop the replay.

Intensive updates to a small RT table that fully fits into a RAM chunk can result in an ever-growing binlog that can never be unlinked until a clean shutdown. Binlogs essentially serve as append-only deltas against the last known good saved state on disk, and they cannot be unlinked unless the RAM chunk is saved. An ever-growing binlog is not ideal for disk usage and crash recovery time. To address this issue, you can configure searchd to perform periodic RAM chunk flushes using the rt_flush_period directive. With periodic flushes enabled, searchd will maintain a separate thread that checks whether RT table RAM chunks need to be written back to disk. Once this occurs, the respective binlogs can be (and are) safely unlinked.

searchd {
...
    rt_flush_period = 3600 # 1 hour
...
}

The default RT flush period is set to 10 hours.

It's important to note that rt_flush_period only controls the frequency at which checks occur. There are no guarantees that a specific RAM chunk will be saved. For example, it doesn't make sense to regularly re-save a large RAM chunk that only receives a few rows worth of updates. Manticore automatically determines whether to perform the flush using a few heuristics.