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Diffstat (limited to 'Documentation/config-gerrit.txt')
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diff --git a/Documentation/config-gerrit.txt b/Documentation/config-gerrit.txt index 121ac8fd8a..dbe390957e 100644 --- a/Documentation/config-gerrit.txt +++ b/Documentation/config-gerrit.txt @@ -3159,6 +3159,53 @@ this threshold times the requested limit will result in an error. Set to + Defaults to no limit. +[[index.pageSizeMultiplier]]index.pageSizeMultiplier:: ++ +When index queries are repeated to obtain more results, this multiplier +will be used to determine the limit for the next query. Using a page +multiplier allows queries to start off small and thus provide good +latency for queries which may end up only having very few results, and +then scaling up to have better throughput to handle queries with larger +result sets without incurring the overhead of making as many queries as +would be required with a smaller limit. This strategy of using a multiplier +attempts to create a balance between latency and throughput by dynamically +adjusting the query size to the number of results being returned by each +query in the pagination. ++ +The larger the multiplier, the better the throughput on large queries, and +it also improves latency on large queries by scaling up quickly. However, a +larger multiplier can hurt latencies a bit by making the "last" query in a +series longer than needed. The impact of this depends on how much the backend +latency goes up when specifying a large limit and few results are returned. +Setting link:#index.maxPageSize[index.maxPageSize] that isn't too large, can +likely help reduce the impacts of this. ++ +A large multiplier with an appropriate link:#index.maxPageSize[index.maxPageSize] +should benefit external index backends such as Elasticsearch more, which have +a relatively high query latency. ++ +For example, if the limit of the previous query was 500 and pageSizeMultiplier +is configured to 5, the next query will have a limit of 2500. ++ +Defaults to 1 which effectively turns this feature off. + +[[index.maxPageSize]]index.maxPageSize:: ++ +Maximum size to allow when index queries are repeated to obtain more results. Note +that, link:#index.maxLimit[index.maxLimit] will be used to limit page size if it +is configured to a value lower than maxPageSize. ++ +For example, if the limit of previous query was 500, pageSizeMultiplier is +configured to 5 and maxPageSize to 2000, the next query will have a limit of +2000 (instead of 2500). ++ +When `index.type` is set to `ELASTICSEARCH`, this value should not exceed +the `index.max_result_window` value configured on the Elasticsearch +server. If a value is not configured during site initialization, defaults to +10000, which is the default value of `index.max_result_window` in Elasticsearch. ++ +Defaults to no limit. + [[index.maxTerms]]index.maxTerms:: + Maximum number of leaf terms to allow in a query. Too-large queries may |