feat: default concurrency changed back from 32 to 16 for transformMap

Author: kirillgroshkov

package.json

@@ -41,7 +41,7 @@
   "devDependencies": {
     "@naturalcycles/bench-lib": "^3.0.0",
     "@naturalcycles/dev-lib": "^15.0.3",
-    "@types/node": "^20.1.0",
+    "@types/node": "^22.1.0",
     "@types/yargs": "^16.0.0",
     "jest": "^29.0.0"
   },

src/stream/transform/transformMap.ts

@@ -40,10 +40,12 @@ export interface TransformMapOptions<IN = any, OUT = IN> {
   /**
    * Number of concurrently pending promises returned by `mapper`.
    *
-   * Default is 32.
+   * Default is 16.
    * It was recently changed up from 16, after some testing that shown that
    * for simple low-cpu mapper functions 32 produces almost 2x throughput.
    * For example, in scenarios like streaming a query from Datastore.
+   * UPD: changed back from 32 to 16, "to be on a safe side", as 32 sometimes
+   * causes "Datastore timeout errors".
    */
   concurrency?: number
 
@@ -120,7 +122,7 @@ export interface TransformMapStatsSummary extends TransformMapStats {
  *
  * Only works in objectMode (due to through2Concurrent).
  *
- * Concurrency defaults to 32.
+ * Concurrency defaults to 16.
  *
  * If an Array is returned by `mapper` - it will be flattened and multiple results will be emitted from it. Tested by Array.isArray().
  */
@@ -129,7 +131,7 @@ export function transformMap<IN = any, OUT = IN>(
   opt: TransformMapOptions<IN, OUT> = {},
 ): TransformTyped<IN, OUT> {
   const {
-    concurrency = 32,
+    concurrency = 16,
     predicate, // we now default to "no predicate" (meaning pass-everything)
     errorMode = ErrorMode.THROW_IMMEDIATELY,
     flattenArrayOutput,

yarn.lock

@@ -1178,20 +1178,13 @@
   dependencies:
     "@types/node" "*"
 
-"@types/node@*", "@types/node@^22.0.0":
+"@types/node@*", "@types/node@^22.0.0", "@types/node@^22.1.0":
   version "22.1.0"
   resolved "https://registry.yarnpkg.com/@types/node/-/node-22.1.0.tgz#6d6adc648b5e03f0e83c78dc788c2b037d0ad94b"
   integrity sha512-AOmuRF0R2/5j1knA3c6G3HOk523Ga+l+ZXltX8SF1+5oqcXijjfTd8fY3XRZqSihEu9XhtQnKYLmkFaoxgsJHw==
   dependencies:
     undici-types "~6.13.0"
 
-"@types/node@^20.1.0":
-  version "20.14.14"
-  resolved "https://registry.yarnpkg.com/@types/node/-/node-20.14.14.tgz#6b655d4a88623b0edb98300bb9dd2107225f885e"
-  integrity sha512-d64f00982fS9YoOgJkAMolK7MN8Iq3TDdVjchbYHdEmjth/DHowx82GnoA+tVUAN+7vxfYUgAzi+JXbKNd2SDQ==
-  dependencies:
-    undici-types "~5.26.4"
-
 "@types/normalize-package-data@^2.4.0":
   version "2.4.4"
   resolved "https://registry.yarnpkg.com/@types/normalize-package-data/-/normalize-package-data-2.4.4.tgz#56e2cc26c397c038fab0e3a917a12d5c5909e901"
@@ -5341,11 +5334,6 @@ unbox-primitive@^1.0.2:
   resolved "https://registry.yarnpkg.com/underscore/-/underscore-1.13.7.tgz#970e33963af9a7dda228f17ebe8399e5fbe63a10"
   integrity sha512-GMXzWtsc57XAtguZgaQViUOzs0KTkk8ojr3/xAxXLITqf/3EMwxC0inyETfDFjH/Krbhuep0HNbbjI9i/q3F3g==
 
-undici-types@~5.26.4:
-  version "5.26.5"
-  resolved "https://registry.yarnpkg.com/undici-types/-/undici-types-5.26.5.tgz#bcd539893d00b56e964fd2657a4866b221a65617"
-  integrity sha512-JlCMO+ehdEIKqlFxk6IfVoAUVmgz7cU7zD/h9XZ0qzeosSHmUJVOzSQvvYSYWXkFXC+IfLKSIffhv0sVZup6pA==
-
 undici-types@~6.13.0:
   version "6.13.0"
   resolved "https://registry.yarnpkg.com/undici-types/-/undici-types-6.13.0.tgz#e3e79220ab8c81ed1496b5812471afd7cf075ea5"