diff --git a/wp-includes/class-wp-site.php b/wp-includes/class-wp-site.php
index 5bfc6430f2..f438264370 100644
--- a/wp-includes/class-wp-site.php
+++ b/wp-includes/class-wp-site.php
@@ -330,14 +330,7 @@ final class WP_Site {
 			wp_cache_set( $this->blog_id, $details, 'site-details' );
 		}
 
-		/**
-		 * Filters a blog's details.
-		 *
-		 * @since MU (3.0.0)
-		 * @deprecated 4.7.0 Use site_details
-		 *
-		 * @param object $details The blog details.
-		 */
+		/** This filter is documented in wp-includes/ms-blogs.php */
 		$details = apply_filters_deprecated( 'blog_details', array( $details ), '4.7.0', 'site_details' );
 
 		/**
diff --git a/wp-includes/ms-blogs.php b/wp-includes/ms-blogs.php
index 7a125c34f8..cdb9691b90 100644
--- a/wp-includes/ms-blogs.php
+++ b/wp-includes/ms-blogs.php
@@ -93,7 +93,8 @@ function get_id_from_blogname( $slug ) {
  * Retrieve the details for a blog from the blogs table and blog options.
  *
  * @since MU (3.0.0)
- * @since 4.9.0 Use get_site_by() internally.
+ *
+ * @global wpdb $wpdb WordPress database abstraction object.
  *
  * @param int|string|array $fields  Optional. A blog ID, a blog slug, or an array of fields to query against.
  *                                  If not specified the current blog ID is used.
@@ -102,46 +103,138 @@ function get_id_from_blogname( $slug ) {
  * @return WP_Site|false Blog details on success. False on failure.
  */
 function get_blog_details( $fields = null, $get_all = true ) {
-	if ( is_array( $fields ) ) {
-		if ( isset( $fields['blog_id'] ) ) {
-			$field = 'id';
-			$value = (int) $fields['blog_id'];
-		} elseif ( isset( $fields['domain'] ) && isset( $fields['path'] ) ) {
-			$field = 'url';
-			$value = $fields['domain'] . '/' . ltrim( $fields['path'], '/' );
-		} elseif ( isset( $fields['domain'] ) && is_subdomain_install() ) {
-			$field = 'domain';
-			$value = $fields['domain'];
+	global $wpdb;
+
+	if ( is_array($fields ) ) {
+		if ( isset($fields['blog_id']) ) {
+			$blog_id = $fields['blog_id'];
+		} elseif ( isset($fields['domain']) && isset($fields['path']) ) {
+			$key = md5( $fields['domain'] . $fields['path'] );
+			$blog = wp_cache_get($key, 'blog-lookup');
+			if ( false !== $blog )
+				return $blog;
+			if ( substr( $fields['domain'], 0, 4 ) == 'www.' ) {
+				$nowww = substr( $fields['domain'], 4 );
+				$blog = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->blogs WHERE domain IN (%s,%s) AND path = %s ORDER BY CHAR_LENGTH(domain) DESC", $nowww, $fields['domain'], $fields['path'] ) );
+			} else {
+				$blog = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->blogs WHERE domain = %s AND path = %s", $fields['domain'], $fields['path'] ) );
+			}
+			if ( $blog ) {
+				wp_cache_set($blog->blog_id . 'short', $blog, 'blog-details');
+				$blog_id = $blog->blog_id;
+			} else {
+				return false;
+			}
+		} elseif ( isset($fields['domain']) && is_subdomain_install() ) {
+			$key = md5( $fields['domain'] );
+			$blog = wp_cache_get($key, 'blog-lookup');
+			if ( false !== $blog )
+				return $blog;
+			if ( substr( $fields['domain'], 0, 4 ) == 'www.' ) {
+				$nowww = substr( $fields['domain'], 4 );
+				$blog = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->blogs WHERE domain IN (%s,%s) ORDER BY CHAR_LENGTH(domain) DESC", $nowww, $fields['domain'] ) );
+			} else {
+				$blog = $wpdb->get_row( $wpdb->prepare( "SELECT * FROM $wpdb->blogs WHERE domain = %s", $fields['domain'] ) );
+			}
+			if ( $blog ) {
+				wp_cache_set($blog->blog_id . 'short', $blog, 'blog-details');
+				$blog_id = $blog->blog_id;
+			} else {
+				return false;
+			}
 		} else {
 			return false;
 		}
 	} else {
-		if ( ! $fields ) {
-			$field = 'id';
-			$value = get_current_blog_id();
-		} elseif ( ! is_numeric( $fields ) ) {
-			$field = 'slug';
-			$value = $fields;
+		if ( ! $fields )
+			$blog_id = get_current_blog_id();
+		elseif ( ! is_numeric( $fields ) )
+			$blog_id = get_id_from_blogname( $fields );
+		else
+			$blog_id = $fields;
+	}
+
+	$blog_id = (int) $blog_id;
+
+	$all = $get_all == true ? '' : 'short';
+	$details = wp_cache_get( $blog_id . $all, 'blog-details' );
+
+	if ( $details ) {
+		if ( ! is_object( $details ) ) {
+			if ( $details == -1 ) {
+				return false;
+			} else {
+				// Clear old pre-serialized objects. Cache clients do better with that.
+				wp_cache_delete( $blog_id . $all, 'blog-details' );
+				unset($details);
+			}
 		} else {
-			$field = 'id';
-			$value = (int) $fields;
+			return $details;
 		}
 	}
 
-	$site = get_site_by( $field, $value );
-
-	if ( ! $site ) {
-		return false;
-	}
-
+	// Try the other cache.
 	if ( $get_all ) {
-		// Prepopulate magic properties for backward compatibility.
-		foreach ( array( 'blogname', 'siteurl', 'post_count', 'home' ) as $detail ) {
-			$site->$detail = $site->$detail;
+		$details = wp_cache_get( $blog_id . 'short', 'blog-details' );
+	} else {
+		$details = wp_cache_get( $blog_id, 'blog-details' );
+		// If short was requested and full cache is set, we can return.
+		if ( $details ) {
+			if ( ! is_object( $details ) ) {
+				if ( $details == -1 ) {
+					return false;
+				} else {
+					// Clear old pre-serialized objects. Cache clients do better with that.
+					wp_cache_delete( $blog_id, 'blog-details' );
+					unset($details);
+				}
+			} else {
+				return $details;
+			}
 		}
 	}
 
-	return $site;
+	if ( empty($details) ) {
+		$details = WP_Site::get_instance( $blog_id );
+		if ( ! $details ) {
+			// Set the full cache.
+			wp_cache_set( $blog_id, -1, 'blog-details' );
+			return false;
+		}
+	}
+
+	if ( ! $details instanceof WP_Site ) {
+		$details = new WP_Site( $details );
+	}
+
+	if ( ! $get_all ) {
+		wp_cache_set( $blog_id . $all, $details, 'blog-details' );
+		return $details;
+	}
+
+	switch_to_blog( $blog_id );
+	$details->blogname   = get_option( 'blogname' );
+	$details->siteurl    = get_option( 'siteurl' );
+	$details->post_count = get_option( 'post_count' );
+	$details->home       = get_option( 'home' );
+	restore_current_blog();
+
+	/**
+	 * Filters a blog's details.
+	 *
+	 * @since MU (3.0.0)
+	 * @deprecated 4.7.0 Use site_details
+	 *
+	 * @param object $details The blog details.
+	 */
+	$details = apply_filters_deprecated( 'blog_details', array( $details ), '4.7.0', 'site_details' );
+
+	wp_cache_set( $blog_id . $all, $details, 'blog-details' );
+
+	$key = md5( $details->domain . $details->path );
+	wp_cache_set( $key, $details, 'blog-lookup' );
+
+	return $details;
 }
 
 /**
diff --git a/wp-includes/version.php b/wp-includes/version.php
index c1388a1fc5..73c996e685 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.9-beta2-41882';
+$wp_version = '4.9-beta2-41883';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.